Classifying, Measuring, and Predicting Users’ Overall Active Behavior on Social Networking Sites AIHUI CHEN, YAOBIN LU, PATRICK Y.K. CHAU, AND SUMEET GUPTA AIHUI CHEN is an assistant professor in the College of Management and Economics at Tianjin University, China. He obtained his Ph.D. at Huazhong University of Science and Technology in China in 2014. His research focuses on social commerce, social networks, and electronic and mobile business. His research has been published in Journal of Information Technology, Journal of Business Research, and other journals. YAOBIN LU is a specially appointed professor in information systems and the associate dean of the School of Management at Huazhong University of Science and Technology in China. He obtained his Ph.D at Huazhong University of Science and Technology in 1997. His research interests include social commerce, mobile commerce, customer trust, electronic commerce, and related topics. He is the author of more than forty publications in various international journals, such as Decision Support Systems, Information Systems Journal, Information & Management, International Journal of Electronic Commerce, Journal of Information Technology, and International Journal of Information Management. Yaobin Lu is the corresponding author of this paper. PATRICK Y.K. CHAU is the Padma and Hari Harilela Professor in Strategic Information Management at the Faculty of Business and Economics of the University of Hong Kong. He obtained his Ph.D. in business administration from the Richard Ivey School of Business at the University of Western Ontario, Canada. His teaching and research interests are in management of information systems, electronic commerce, and research methodology. His work has appeared in3 leading information systems journals such as Journal of Management Information Systems, MIS Quarterly, Journal of the Association for Information Systems, Decision Sciences, Decision Support Systems, Information & Management, and International Journal of Electronic Commerce. SUMEET GUPTA is chair of the Research Division at the Indian Institute of Management Raipur, India. He received his M.B.A. and Ph.D. from the National University of Singapore. He was associated with the Logistic Institute-Asia Pacific, Singapore as a research fellow and worked on several projects with the ASEAN Secretariat, DFS Gallerias, and SAP A.G., Walldorf, Germany. He is the author of more than fifty publications in leading international journals (Decision Support Systems, International Journal of Electronic Commerce, and others) and conference proceedings (ICIS, AMCIS, ECIS, PACIS, and others). He has also published many Journal of Management Information Systems / Winter 2014, Vol. 31, No. 3, pp. 213–253. Copyright © Taylor & Francis Group, LLC ISSN 0742–1222 (print) / ISSN 1557–928X (online) DOI: 10.1080/07421222.2014.995557 214 CHEN, LU, CHAU, AND GUPTA book chapters. His research interests include supply chain management and business analytics. ABSTRACT: Although understanding the role of users’ overall active behavior on a social networking site (SNS) is of significant importance for both theory and practice, the complexity and difficulty involved in measuring such behavior has inhibited research attention. To understand users’ active behaviors on an SNS, it is important that we identify and classify various types of online behaviors before measuring them. In this paper we holistically examine users’ active behaviors on an SNS. Toward this end, we conduct three studies. First, we classify active behaviors on an SNS into four categories using the Delphi method. Then, we develop a measurement model and validate it using the data collected from an online survey of 477 SNS users. The measures of the developed instrument exhibit satisfactory reliability and validity and are used as indicators of the latent constructs. This instrument is then used in a predictive model based on commitment theory and tested using data from 1,242 responses. The results of data analysis suggest that affective commitment and continuance commitment are good predictors of overall active behavior on an SNS. This study complements the existing research on social media, cocreation, and social commerce. Most important, this study provides a theoretically sound measurement instrument that addresses the complex characteristic of overall active behavior on an SNS and which should be useful for future research. The findings of this study have important implications for practice as they highlight managing and stimulating users’ active behaviors on an SNS. KEY WORDS AND PHRASES: Delphi study, measurement model, social media, social networking site, user commitment, users’ active behavior. A SOCIAL NETWORKING SITE (SNS) IS A FORM OF ONLINE COMMUNITY through which users can connect with the people within and beyond their social circle. The pervasiveness of services offered by SNSs and their increasing and widespread influence as a source of information, as a marketplace, and as a setting for social contact has sparked research interest about the behavior of people on an SNS [14, 90]. Recent findings [92, 98] about the significant importance of users’ active involvement and participation has further catalyzed this research interest. Active behavior and lurking (passive) behavior are two common types of behaviors on an SNS [81, 95]. Active behavior refers to activities such as content creation, information sharing, meeting new people online and chatting with them, joining groups, talking about hobbies and personal interests, and posting or uploading videos or photos [9, 82], which require use of active functions provided by the SNS. Lurking behavior refers to passive browsing of social network content [9, 82]. Depending on a user’s normal and regular behavior (active or passive), the user is termed an active user or a passive user [11, 76]. When individuals choose to actively participate in the communication, they are explicitly deciding to contribute their time, energy, attention, knowledge, and relationships [15]. An active user actively contributes to the content and relationships (e.g., posting comments or commenting USERS’ ACTIVE BEHAVIOR ON SNSS 215 on a comment) on an SNS. A passive user, also known as a lurker, browses the content on the SNS but rarely contributes. According to Nonnecke and Preece [75], such lurkers constitute around 90 percent of total members in online communities. Lurkers add hardly any value to the growth of an online community [76] except for a meager contribution to its branding and image building [92]. Some studies have reported active behavior of members as fundamental to the growth of an SNS. For example, Carroll [16] found that active users positively influence the sales revenue of an SNS. Similarly, Lu and Hsiao [63] concluded that greater activity on an SNS has the potential to increase revenues earned through advertising and subscription. Trusov et al. [105] also reported the positive influence of users’ activity level on the success of an SNS. A successful SNS is characterized by a growing network of social relationships, accumulation of user-generated content, and increasing volume of site visits and traffic [21], all of which are necessary for market capitalization and revenue generation [16]. Active behavior on an SNS enhances social activity, such as browsing profiles, exchanging comments, and reciprocating favors, which ultimately leads to growth and expansion of social relationships on the SNS [21, 51]. Moreover, active users of an SNS contribute to the user-generated content, such as photos, videos, and blogs. User-generated conrent contributes to the wealth of an online community and increase its network externalities, which in turn further promotes and propagates the acceptance of the SNS. Furthermore, active behavior boosts the volume of site visits and traffic, which attracts advertisers and helps in generating extra revenues [21]. Active Behavior Research Several researchers have examined the active behaviors of users of SNSs. We can categorize the research into three areas. First, researchers employing the social identity perspective have analyzed the process of self-conception on an SNS [26], which comprises a set of compatible and interrelated components, such as social comparison, intergroup relations, self-enhancement, and social categorization. All of these constitute active behavior on an SNS [45]. However, these studies have reported mixed findings. Although some scholars have argued that active behavior on an SNS increases users’ social capital [18] and perceived social support [61], reduces users’ perceived stress and loneliness, and ultimately leads to higher psychological well-being and even physical health [7, 26, 41, 72], others have indicated that active behavior on an SNS contributes little to users’ social capital and social support. Such scholars have argued that active behavior increases loneliness [6, 106], as the user may ignore the real world. Thus, we can construe that the role of active behaviors on an SNS depends upon the type of active behavior [7]. It is imperative, therefore, to accurately understand the behavior of active users on SNSs. 216 CHEN, LU, CHAU, AND GUPTA In a second area of research into the active behavior of SNS users, investigators have examined such behavior as a contextualized form of cocreation. Cocreation is an evolutionary process that occurs between the firm and users as well as within the community of users [91]. Active behavior on an SNS can contribute content and relationship resources to the community [21, 61]. These resources become valuable through mutual interaction among SNS users. Thus, SNS users often act as “partial employees” of SNSs [111], because they are the primary human resources who coproduce and generate the excitement and services that determine the level of traffic in the community. As partial employees of SNSs, they can contribute by engaging in various active behaviors that improve the performance of SNSs. Zwass [114, p. 31] emphasized the need for much contextualized research to explore how various cocreation patterns are performed. A third line of investigation into the active behavior of SNS users has employed the social commerce perspective in emphasizing the fundamental role of active behavior on an SNS. Social commerce involves using Web 2.0 technologies and infrastructure to support online interactions and user contributions to assist in online buying and selling of products and services [81]. Researchers have indicated that customers rely on social behavior to access others’ knowledge and experiences so as to make better-informed and accurate purchase decisions [48, 56]. Thus, the fundamental social behavior can facilitate commerce by reducing uncertainty and aiding customers in making rational decisions [66, 85]. Researchers have also noted that active behavior on SNSs is a major force in the marketplace [44]. SNSs provide companies with tools to launch targeted campaigns based on their community users’ profiles [102]. Users can participate in these campaigns by posting comments and interacting with community members. Another key characteristic of social networks is the speed with which information is dissemminated. The information in social networks spreads like an epidemic, reaching large audiences through users’ sharing behavior [102]. Thus, different types of active behaviors have different effects on a firm’s marketing function. Heinonen [44] indicated that research is needed to understand the implications of each activity in order to identify the types of activities that are needed or desirable. Some activities may influence the company image and brand positively, but others may not be so desirable. The foregoing discussion underlines the importance of classifying various types of behavior performed by active users on an SNS. A user’s overall active behavior on an SNS incorporating different types of active behaviors has not been examined yet, perhaps because of the inherent difficulty underlying measuring the large and complex activities performed on an SNS. Thus, although SNSs have been studied widely, the endeavor to understand users’ overall active behavior on them is still in its nascent stage. This study first develops a complete measurement instrument for assessing users’ overall active behavior on an SNS and then develops a model to validate it empirically. The methodology is based on the measurement development paradigm proposed by Churchill [27], which has been adopted in IS studies [10, 29]. This USERS’ ACTIVE BEHAVIOR ON SNSS 217 paradigm includes four phases: (1) construct domain specification, (2) construction of items, (3) data collection, and (4) measures purification. Each phase focuses on satisfying the validity and reliability concerns about the construct through iterative development and testing. To achieve this goal, this study is divided into three parts. The first part aims at developing appropriate categories of behaviors that would reveal the essence and contribution usually made by an active user of an SNS. This helps generate a pool of items required for the development of indicators. The second part aims at developing a measurement model to operationalize these behaviors and testing them in an empirical setting. In the third part, nomological validity [10] is tested. Nomological validity is the ability of a new measure to perform as expected in a network of well-established measures [10]. We place the empirically validated measurement model in a research study that investigates the mind-sets driving the overall active behavior on an SNS. The research model in this study is based on commitment theory and is empirically examined using data collected from a survey of 1,242 actual users of Renren.com, the biggest SNS and the equivalent of Facebook in China. This process further validates the construct, as well as evaluates the nomological validity of the proposed measurement instrument. Users’ Active Behavior on Online Communities and SNSs AN ONLINE COMMUNITY IS GENERALLY REGARDED AS a cyberspace domain supported by computer-based information technology and centered upon communication and interaction of participants to generate member-driven content that results in a relationship [57, 64]. Traditional online communities are of four types: (1) interest communities (such as the open source software community), in which people who share an interest or expertise on a specific topic gather to communicate with one another [33]; (2) relationship communities (such as AIDS and Hepatitis B bulletin board system communities), in which people with similar experiences gather and form meaningful relationships [65]; (3) fantasy communities (such as Second Life and World of Warcraft players), which usually refer to online game player sites where people gather to fulfill their fantasies [113]; and (4) transaction communities (such as the community embedded in Amazon. com), which focus on transaction needs and provide people with trading information [64]. Active behavior in these communities has been conceptualized as posting behavior [75, 96]. Nonnecke et al. [76] noted that whereas posters frequently display extrovert behavior, lurkers exhibit introvert behavior limited to observing and browsing postings. This poster-lurker dichotomy, however, describes the two end points of the SNS behavior spectrum and does not consider the activity level anywhere between the end points (such as for users who are somewhat active or mildly active). Kim [52] proposed a more thorough framework that models users’ behavior specifically in an online community. This framework differentiates among several active behavioral roles: (1) the visitor, who exhibits unstructured 218 CHEN, LU, CHAU, AND GUPTA participation; (2) the novice, who invests time and effort in order to become an active member; (3) a regular member, who exhibits full commitment; and (4) the leader, who sustains membership participation and guides interactions of others [79]. Preece and Shneiderman [89] proposed a reader-to-leader framework that emphasizes different needs and values at different levels of active behavior: (1) reader, who only consumes articles/content; (2) contributor, who contributes some content to the community; (3) collaborator, who participates in group projects; and (4) leader, who leads the community and moderates discussions. Active behavior has been conceptualized as high intensity of SNS use [62, 87]. A few studies have applied these conceptualizations of active behavior to the SNS context. Rau et al. [92], for example, classified the respondents into posters and lurkers based on their posting frequency. This conceptualization asserts that active behavior is content contribution behavior, and lurking behavior is content consumption behavior [82, 92]. However, although these frameworks describe the spectrum of active behavior to some extent, they lose sight of the collaboration and socialization roles of active behavior. Online Communities Versus Social Networking Sites SNSs are different from traditional online communities in organization structure and function, and therefore the users’ behavior pattern on SNSs is different from that of traditional online communities. SNSs are gnerally defined as web-based services that allow individuals to (1) construct a public or semipublic profile within a bounded system, (2) articulate a list of other users with whom they share a connection, and (3) view and traverse their list of connections and those of others within the system [12]. People go to SNSs mainly to satisfy their socioemotional needs rather than their informational needs [92, 102]. Although there are relationship communities that are designed to exchange emotional support similar to that offered by SNSs, such exchange occurs primarily among strangers, rather than among offline acquaintances as on an SNS [92]. Consequently, the users’ motivation for action and their behavioral pattern on an SNS are quite different from that of other types of online communities. Moreover, SNSs comprise both content and social linkages [39], which means the active behavior on an SNS should include both cotent-related behavior and relationship-related behavior. Shao [97] proposed that people perform a variety of activities on an SNS: (1) consumption of information and entertainment, (2) participation in social interaction and community development, and (3) production of self-expression and self-actualization. Heinonen [44] divided social media activities into three categories depending on the motivation behind the activity: (1) information-processing activities, (2) entertainment activities, and (3) social connection activities. These researchers conceptualize active behavior as the various activities users perform using the active functionalities of USERS’ ACTIVE BEHAVIOR ON SNSS 219 SNSs to satisfy their various needs [44, 97]. However, these frameworks are limited in that they do not discuss the cocreation pattern and the resources that active behaviors contribute to the SNS. Therefore, this study develops a framework describing users’ specific active behaviors on an SNS, depicting users’ contribution of content and relationship, and reveals the cocreation pattern in the context of an SNS. Users' Active Behavior on SNSs A few studies [12, 61, 92] on users’ active behavior on SNSs have examined various kinds of active behaviors. Broadly speaking, these active behaviors can be grouped into four categories, namely, content creation, content transmission, relationship building, and relationship maintenance. This categorization conforms with Boyd and Ellision’s [12] assertion that content and relationships are two main elements of social network services used primarily by users. These two elements, that is, content generation and social interaction, can also be understood as relationship contribution activities in the social media [81]. Researchers posit that individuals use social media to participate in social networks, which enables them to create and share content, communicate with one another, and build relationships [2]. Studies on content creation have focused mainly on factors that motivate a user to create or generate content in an online service. For example, Zhang and Zhu [112] explored the intrinsic motivation of open content contributors in an open source community. Daugherty et al. [30] explored consumer motivations for creating usergenerated content in the social media. Nov et al. [78] explored the factors that affect individuals’ metaknowledge contribution in a popular photo-sharing site, and Nosko et al. [77] examined the relationship between users’ personal information and their information disclosure behavior in online social networking profiles. A few other researchers have also examined the value of user-generated content. For example, Park et al. [83] concluded that user-generated reviews can influence consumers’ purchase intention, and Ghose and Ipeirotis [38] demonstrated the economic value of user-generated content. In summary, prior literature suggests that content creation behavior is an important indicator of users’ participation in SNSs and that usergenerated content is an essential contribution to SNSs [19, 78]. Studies on content transmission focus on why an SNS user engages in sharing behavior, such as sharing blogs, photos, and videos [12]. Previous studies have investigated this issue from various perspectives. Chiu et al. [25] integrated social cognitive theory and social capital theory to construct a model for investigating the factors motivating people’s knowledge sharing in virtual communities. Acquisti and Gross [1] investigated the motivation and privacy issues associated with information-sharing behavior on Facebook among college students and faculty members. And Garg et al. [37] classified the content diffusion in social networks into two categories, namely, influence (by a system or a peer) and discovery (by active search), and then developed an empirical method to measure content discovery and content diffusion in online social networks. Users’ content transmission 220 CHEN, LU, CHAU, AND GUPTA behavior is vital for online marketing (such as online word of mouth) performance [37] and extracting economic value from user-generated content [38]. Studies on relationship building are based on the premise that SNSs can help strangers connect with each other based on their shared interests, political views, or activities [12]. After joining an SNS, users are prompted by the system to identify others with whom they have a relationship within the system. For example, LinkedIn has a referral system so that these users can be introduced, through a chain of friends of a friend, to the person they intend to meet. Building relationships on an SNS can help users enhance their online social capital [106], as well as accelerate the transmission of information and thus generate social and economic value [100]. For example, Vergeer and Pelzer [106] examined the influence of online relationship building behavior on offline and online network capital and well-being.. Similarly, Antheunis et al. [6] investigated strategies to reduce uncertainty in relationship building activity through SNSs. A few other studies in this category have focused on relationship building between customers and vendors through social media. For example, Wang and Head [109] analyzed the influence of Webcharacteristics in building consumer relationship mechanisms in online services. Social relationships are dynamic and require active maintenance for their survival. If no effort is made by the relationship partners, the relationships tend to decay over time [94]. Roberts and Dunbar [94] examined the effects of social network size, emotional closeness, and type of relationship (kinship vs. friendship) on users’ relationship maintenance behavior in the social networks. Similarly, Park et al. [84] also examined the influence of the need for affiliation on the motivations for relationship maintenance in the context of Facebook. Thus, active behavior on an SNS involves content creation and content transmission, relationship building, and relationship maintenance. In this study, we conceptualize the overall active behavior on an SNS as users’ specific activities using the active functionalities in the SNS, which includesusers’ contributions to content and relationship and reveals the cocreation pattern on an SNS. Active user in this study is defined as an individual who participates in these four kinds of active behaviors— content creation, content transmission, relationship building, and relationship maintenance—normally and regularly. Although the four proposed categories are based on a literature review, they have not been empirically investigated. We now examine these categories empirically using a Delphi study. The Delphi Study Although we could have conducted a traditional survey or literature review [10] to gather users’ various active behaviors on SNSs and then classified them into categories through a content analysis or card-sorting approach [70], the Delphi method is a superior method because it involves rigorous queries from experts and stakeholders [80]. A Delphi study attempts to obtain consensus from a group of experts using repeated responses on questionnaires and controlled feedback [74]. A key advantage of this approach is that it avoids direct confrontation among experts. USERS’ ACTIVE BEHAVIOR ON SNSS 221 The process used in this study involved two panels consisting of nineteen participants. The first panel comprised ten active users of SNSs who logged in to their SNS daily and frequently participated in various contribution activities on the SNS. We selected them as the most active group (called “popular stars” in online social networks), and all of them claimed to be active users of an SNS. Although not all the behaviors of active users on an SNS can be regarded as active behavior, active users carry out active behavior normally and regularly. Thus, they can provide a relatively complete item pool of active behavior. The second panel comprised nine academic scholars who had research experience and publications in online human behavior and were familiar with the concept of users’ overall active behavior on an SNS. They can guard the completeness and conciseness of the item pool. As advised by Okoli and Pawlowski [80], a panel size of nine or ten is considered appropriate in a Delphi study of this nature. We chose to have two panels of almost equal size so as to maintain a balance between the two groups of panelists and so that the opinions and comments obtained from the study would remain unbiased toward either side. Following standard Delphi procedures [80], we carried out the Delphi study in three phases: a brainstorming phase to generate a list of users’ active behaviors on SNSs, a narrowing-down phase, and finally a classification phase to classify users’ active behaviors identified in the previous phases. Figure 1 outlines the process of administering the study. In the first phase, ten panelists were asked to consider the functionalityand list all possible (at least ten) actions/behaviors carried out by a user on an SNS. A total of thirty-four active behaviors were identified at the end of this phase (see Table 1). In the second phase, each panelist was asked to select—not rank—at least ten active behaviors that they considered important in contributing to either content or relationships [61]. This process reduced the list of active user behaviors to twenty-seven. (The seven behaviors that were discarded are shown in italics in Table 1.) The last phase in the Delphi study was classification of behaviors. For the purpose of classification, the panelists were asked to ponder two questions: (1) Does the behavior contribute either to content or relationship in an SNS? and (2) What is Phase 1 Panelists: Ten active users of an SNS Brainstorming Step 1: Panelists were asked to list at least ten user behaviors in an SNS Step 2: Panelists were asked to verify the behavior list and suggest additional items if they saw the need Panelists: All nineteen experts Phase 2 Step 1: Panelists were asked to select (not rank) at least ten active behavioral items that they considered Narrowing down important for contributing either content or relationships Step 2: Items selected by over 50 per cent of panelists were retained Panelist: All nineteen experts Phase 3 Step 1: Panelists were asked to classify the retained items into four categories (content creation, content Classifying transmission, relationship building, and relationship maintenance) Step 2: Aggregated the responses statistically, and iterated the process until responses attained Figure 1. The Administration Process in the Delphi Study 222 CHEN, LU, CHAU, AND GUPTA Table 1. Users’ Active Behaviors in SNSs (Thirty-Four Items) No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 Item Posting blogs/articles Changing/posting current status Posting photos/videos Updating/editing profile Tagging photos Sharing resources from other sites on SNSs Sharing friends’ sharing Sharing friends’ blogs Sharing friends’ photos Sharing or transmitting friends’ statuses Creating groups or public profiles Visiting public profiles or discussion board Joining groups or public profiles Creating events and sending invitations Searching friends and sending application for adding friends Accepting application for adding friends Sending private messages to nonfriends Responding to invitations to participate in events from groups Interacting with groups Participating in the topic of friends Commenting on photos Chatting with friends through SNSs Looking at personal information of friends Visiting friends’ profiles Looking at news about friends Looking at photos of friends Reading my news feed Reading posts on my wall Reading posts on friends’ walls Posting on friends’ walls Reading private messages from friends Sending private messages to friends Playing social games in SNSs Using social applications in SNSs Note: Items 28–34 were discarded in the second phase. the specific result essentially generated by that specific behavior? Panelists were also asked to provide a brief explanation or justification for their classification. The iterations were stopped at the fourth round, as all panelists declared that they had sufficiently deliberated on the issue and were satisfied with the final classification. After getting stable responses from all panelists, we examined the level of consensus statistically, both through the level of agreement and the coefficient of variation among panelists. Consensus, which can be either agreement or disagreement with a statement, USERS’ ACTIVE BEHAVIOR ON SNSS 223 can be defined as a percentage higher than the average percentage of majority opinion, and majority is usually defined as a percentage above 50 percent [107]. As shown in Table 2, the panelists’ agreement reached an acceptable level of consensus for all the items except one. The agreement level of one item (tagging photos) fell below the lowest acceptable level of 50 percent, suggesting that tagging photos might be a complex behavior contributing to both content and relationship and should be investigated separately [78]. Table 2. Classification Results of the Delphi Study Dimension Content Creation (CC) Content Transmission (CT) Relationship Building (RB) Relationship Maintenance (RM) Item Posting blogs/articles Changing/posting current status Posting photos/videos Updating/editing profile Tagging photos (dropped) Sharing resources from other sites to SNSs Sharing friends’ sharing Sharing friends’ blogs Sharing friends’ photos Sharing or transmitting friends’ statuses Creating groups or public profiles Visiting public profiles or discussion board Joining groups or public profiles Creating events and sending invitations Searching friends and sending application for adding friends Accepting application for adding friends Sending private messages to nonfriends Responding to invitations to participate in events from groups Interacting with groups Participating in the topic of friends Commenting on photos Chatting with friends through SNSs Looking at personal information of friends Visiting friends’ profiles Looking at news about friends Looking at photos of friends Reading my news feed (dropped) Agreement level (percent) Coefficient of variation 94.7 94.7 94.7 94.7 47.4 100 .242 .242 .242 .242 1.08 0 100 100 100 94.7 0 0 0 .242 94.7 78.9 .242 .531 89.5 84.2 .352 .445 89.5 .353 100 0 94.7 100 78.9 100 94.7 94.7 100 100 100 100 57.9 .242 0 .531 0 .242 .242 0 0 0 0 .876 224 CHEN, LU, CHAU, AND GUPTA We calculated the coefficient of variation for each item, and the results show a very high level of consensus for all the items except two (see Table 2). Tagging photos and reading my news feed showed poor consensus (V > 0.8) [32]. Following von der Gracht [107], we dropped these two items from further analysis. Thus, the final list contains twenty-five user active behaviors. It is important to note that some SNSs also allow commercial applications within the SNS, and hence there may be some active behaviors on the SNS that are related to “social commerce” [60]. However, none of the items describing users’ commercial behavior were incorporated in our Delphi results. Nevertheless, the items identified in this study can represent the primary active behvior on an SNS, for three reasons. First, most SNSs are mainly designed to satisfy users’ social needs [12], rather than commercial needs. Commercial activity is not the main function, but rather an extension of SNSs [108]. Second, although a few social commerce sites have emerged in recent years through a combination of the social function and the commercial function, users can only realize the commercial behaviors by carrying out the basic social activities. For example, Liang et al. [61] designed items to assess a user’s intention to participate in social commerce by referring to recommend shopping information and products and receive shopping information and products on SNSs. These activities could only be realized through “sharing friends’ blogs,” “sharing friends’ photos,” “visiting friends’ profiles,” or “looking at news about friends.” Third, although the student sample may bias the results to some extent, the mainstream SNSs (e.g., Facebook) were designed first for students in universities and later were extended to other populations in the society. College students are a significant segment of SNS users. Eighty-five percent of U.S. college students use Facebook, and 95 percent of Chinese students use Renren [21]. Also, student samples are widely used in SNS studies [21–23]. Hence, we consider using the student sample as appropriate for the current research. Measurement Model Development WE USED THE RESULTS OBTAINED FROM THE DELPHI STUDY to develop a measurement model that can be used in further research related to active behavior on an SNS. After categorizing twenty-five user active behaviors in four groups, we conducted a second study to test the validity of this classification. Method Data for this study were collected using an online survey. The survey instrument comprises twenty-five behavior items obtained from the Delphi study. Respondents were asked to rate the frequency of these behaviors on SNSs on a seven-point scale ranging from 1 (never) to 7 (very frequently). A pilot test of twenty subjects suggested that at least five minutes were needed to complete the questionnaire. USERS’ ACTIVE BEHAVIOR ON SNSS 225 Our sampling frame was users of Renren (www.renren.com), the Chinese equivalent of Facebook. A survey hyperlink was placed on the forums of Renren to solicit participants. This hyperlink could be shared by users and thus could be spread virally throughout the SNS. To attract more participants, each respondent got ¥1 as a reward for participating. We paid the respondents through a third-party payment platform called Alipay. To ensure that each respondent responded only once, we noted each participant’s IP (Internet protocol) address and demographic information. Five hundred forty-seven Renren users completed the online survey in twenty days. After deleting responses with missing values and those completed in less than five minutes, we retained 477 valid questionnaires. The demographics of these respondents are summarized in Table 3. On comparing the demographic features of the current study with that of the large-scale national survey about SNS users in China [28], we found that only the identity feature showed significant difference. A plausible explanation is that our survey was aimed at active users on SNSs, rather than general users [28], and students generally exhibit more active behavior [21]. Thus, our sample is representative of the entire active population of Renren users. Results Exploratory Factor Analysis After obtaining the survey results, we then performed exploratory factor analysis using principal component analysis with Varimax rotation on the collected data. Both the Table 3. Descriptive Statistics of Survey Respondents Category Gender Age Education Identity Relationship status Items Male Female ≤ 19 20–29 ≥ 30 High school or below Junior college Undergraduate Graduate or above Students Nonstudents Single Just in love Married Sample (N = 477) CNNIC Sample Frequency Percentage Percentage 220 257 36 419 22 31 46.1 53.9 7.5 87.8 4.6 6.5 53.7 46.3 29.0 56.8 14.2 7.2 135 281 30 28.3 58.9 6.3 37.4 42.7 12.6 263 214 264 156 57 55.1 44.9 55.3 32.7 11.9 Chi-square differences χ2(1) = 1.28 (p = .258) χ2(2) = 2.674 (p = .102) χ2(3) = 6.335 (p = .096) 26 χ2(1) = 17.450 (p = .000) 74 There are no data about participants’ relationship status in the CNNIC’s survey in 2012. 226 CHEN, LU, CHAU, AND GUPTA Bartlett’s test of sphericity (770.47 at p = 0.000) and the Kaiser–Meyer–Olkin measure of sampling adequacy (KMO = 0.922) indicated that there were sufficient interitem correlations within the data for conducting factor analysis. The results of factor analysis show that five items were dropped for weak loadings and twenty items are clearly loaded on four constructs (see Table 4). The four factors together account for 72.2 percent of the total variance. The items for the two content constructs show clear and clean loadings, with three and five items loaded on the two constructs, content creation and content transmission, respectively. We therefore keep the original labels, CC (content creation) and CT (content transmission), for them. The items for the two relationship constructs, however, did not load on the two constructs as we expected. Some of the items for relationship building loaded on relationship maintenance, and vice versa. On closer examination, we found that the six items that loaded on the first factor were all related to relationships among Table 4. Results of the Exploratory Factor Analysis (Twenty Items) Component Item 1 2 3 4 Posting blogs/articles Changing/posting current status Posting photos/videos Sharing resources from other sites on SNSs Sharing friends’ sharing Sharing friends’ blogs Sharing friends’ photos Sharing or transmitting friends’ statuses Creating groups or public profiles Visiting public profiles or discussion boards Joining groups or public profiles Creating events and sending invitations Responding to invitations to participate in events from groups Interacting with groups Searching friends and sending application for adding friends Accepting application for adding friends Looking at personal information of friends Visiting friends’ profiles Looking at news about friends Looking at photos of friends .069 .284 .195 .240 .292 .195 .142 .208 .047 .271 .194 .159 .246 .364 .221 .201 .188 .128 .222 .254 .233 .798 .708 .783 .752 .654 .179 .257 .286 .754 .818 .825 .834 .797 .153 .151 .147 .224 .230 .771 .762 .764 .183 .222 .184 .172 .112 .230 .119 .101 .141 .262 .180 .719 .802 .187 .187 .209 .143 .074 .679 .817 .864 .851 .827 .181 .198 .182 .156 .125 .258 .159 .143 .131 .203 .085 .104 .135 .156 .136 Eigenvalue Variance % Cumulative % 4.400 4.010 3.850 2.187 22.000 20.049 19.248 10.935 22.000 42.049 61.297 72.232 Notes: All the boldface factor loadings are significant at the 0.001 level. USERS’ ACTIVE BEHAVIOR ON SNSS 227 individuals (such as “searching friends and sending application for adding friends,” “accepting application for adding friends,” and “looking at personal information of friends”), which indicates that users were devoting their efforts to personal relationship building or maintenance. We therefore label this construct individual relationship contribution (IRC). Similarly, the other six items that load on the second factor indicate that they are all related to relationships between individuals and groups. These items reflect users’ efforts to build or maintain group relationships. Accordingly, we label this construct group relationship contribution. Confirmatory Factor Analysis To confirm the factor structure obtained in the exploratory factor analysis, we conducted a confirmatory factor analysis using AMOS (version 7.0). Each item was restricted so as to load on its prespecified factor, and the factors themselves were allowed to correlate freely (see Figure 2). The results of the initial estimation of the first-order factor model were not satisfactory, as the chi-square value of 780.623 (df = 164, p < 0.05) was significant. This is quite obvious, given the large sample size. Other fit indices revealed a moderate fit (comparative fit Index (CFI) = 0.911; goodness of fit index (GFI) = 0.850; adjusted goodness of fit index (AGFI) = 0.809; non-normed fit index (NFI) = 0.891; tucker-lewis index (TLI) = 0.897; Root Mean Square Error of Approximation (RMSEA) = 0.089). We then optimized the measurement model based on modification indices and dropped “accepting application for adding friends,” “sharing resources from other sites to SNSs,” “visiting public profiles or discussion board,” and “sharing friends’ sharing” step by step. At each step we examined the fit indices. After these deletions, the fit indices demonstrated a good fit between the model and the data (χ2/df = 2.856; CFI = 0.965; GFI = 0.932; AGFI = 0.906; NFI = 0.947; TLI = 0.957; RMSEA = 0.062). Thus, we retained sixteen items loaded on four factors. Next, we tested for reliability and validity. Construct Reliability The four factors have Cronbach’s alphas higher than 0.8, indicating adequate construct reliability. The composite reliabilities of each construct are all above 0.9, indicating that the constructs used in this study have acceptable levels of individual item reliability (see Table 5). Convergent Validity and Discriminant Validity We confirmed convergent validity by examining both the average variance extracted (AVE) and indicator loadings. As shown in Table 5, all AVE values were higher than the recommended level of 0.5 [34]. The standardized path loadings of all items in the confirmatory factor analysis ranged from 0.661 to 0.925, which are all significant at the level of 0.001 (Figure 2) [24]. This shows a good convergent validity [24]. 228 CHEN, LU, CHAU, AND GUPTA CC1 .726 .827 CC2 CC3 Content Creation .785 .593 CT1 .867 .925 CT2 CT3 Content Transmission .491 .829 .457 IRC1 IRC2 .661 .844 .643 .909 Individual Relationship .883 Contribution IRC3 .568 IRC4 .856 IRC5 .474 GRC1 GRC2 .777 .725 .771 Group Relationship .774 Contribution GRC3 GRC4 .843 GRC5 Figure 2. Confirmatory Factor Analysis Results of First-Order Factor Measurement Model Table 5. Descriptive Statistics, Reliability, and Average Variance Extracted Latent variable Mean SD Cronbach’s alpha Composite reliability AVE Content creation Content transmission Group relationship contribution Individual relationship contribution 3.468 3.726 3.123 4.790 1.307 1.435 1.387 1.343 .833 .904 .884 .917 .900 .940 .915 .938 .750 .840 .684 .753 We evaluated discriminant validity of the factors using various approaches. For each pair of factors, we compared the χ2 value for the baseline model with the constraint model (by constraining their correlation as 1). The χ2 difference test was USERS’ ACTIVE BEHAVIOR ON SNSS 229 Table 6. Pairwise Discriminant Validity Analyses Two-factor combinations for constrained measurement models Content creation & Content transmission Content creation & Individual relationship contribution Content creation & Group relationship contribution Content transmission & Individual relationship contribution Content transmission & Group relationship contribution Individual relationship contribution & Group relationship contribution χ2 χ2 difference 286.782 331.508 294.372 309.928 285.984 328.210 6.908** 51.634*** 14.498*** 30.054*** 6.11* 48.336*** Notes: The unconstrained measurement model: χ2 (98) = 279.874. ***p ≤ .001; **p ≤ 0.01; *p ≤ 0.05. performed for each pair of factors (a total of six tests). The results of these tests showed significant differences in each case, suggesting that none of the six pairs of constructs could be merged as a single construct, thus demonstrating discriminant validity. The results of χ2 difference tests are presented in Table 6. We also assessed discriminant validity was by comparing the square root of the AVE for each construct with the correlations between the construct and other constructs [8]. As shown in Table 7, the square root of the AVE (diagonal elements) was found to be larger than the correlations (off-diagonal elements) between constructs, suggesting discriminant validity. We again performed a principal component analysis on the final list of sixteen items left after the confirmatory factor analysis. The results of the analysis, presented in Table 8, indicate that each item loaded onto only one factor, and no single factor accounted for the majority of the variance. After rotation, each factor accounted for less than 25 percent of the total variance, and all four factors accounted for 75.3 percent of the total variance. Together with all the foregoing tests, the measures developed in this study demonstrate satisfactory construct reliability and validity and thus serve as good Table 7. Construct Correlation Matrix and Square Root of Average Variance Extracted Correlations CC CT GRC IRC CC CT GRC IRC .866 .521 .564 .432 .917 .514 .447 .827 .442 .868 Notes: Diagonal elements in boldface display the square root of AVE. CC = content creation, CT = content transmission, GRC = group relationship contribution, IRC = individual relationship contribution. 230 CHEN, LU, CHAU, AND GUPTA Table 8. Results of the Principal Component Analysis (Sixteen Final Items) Component Final items Posting blogs/articles Changing/posting current status Posting photos/videos Sharing friends’ blogs Sharing friends’ photos Sharing or transmitting friends’ statuses Creating groups or public profiles Joining groups or public profiles Creating events and sending invitations Responding to invitations to participate in events from friends Interacting with groups Searching friends and sending application for adding friends Looking at personal information of friends Visiting friends’ profiles Looking at news about friends Looking at photos of friends Eigenvalue Variance % Cumulative % Labels 1 2 3 4 CC1 CC2 CC3 CT1 CT2 CT3 GR1 GR2 GR3 GR4 .069 .283 .196 .219 .168 .229 .061 .196 .160 .262 .367 .210 .191 .230 .241 .212 .793 .756 .779 .683 .143 .185 .260 .823 .868 .830 .162 .107 .189 .221 .774 .792 .780 .219 .210 .157 .232 .146 .156 .247 GR5 IR1 .196 .680 .821 .206 .180 .190 .138 .101 IR2 IR3 IR4 IR5 .838 .883 .873 .852 .191 .171 .148 .104 .150 .123 .103 .177 .105 .139 .159 .148 3.858 24.116 24.116 3.459 2.513 2.218 21.621 15.707 13.862 45.737 61.444 75.360 Notes: All the boldface factor loadings are significant at the 0.001 level. indicators of the four latent constructs. The final survey instrument is presented in Table 8. Second-Order Factor Model Because the four identified factors demonstrated good reliability and validity, we tested a second-order factor model in which these four factors are viewed as indicators of the second-order construct “overall active behavior in an SNS” (Figure 3). We consider the overall active behavior in an SNS as a reflective construct for three reasons. First, the theoretical direction of causality is from the second-order construct to the first-order constructs, which is the characteristic of a reflective construct [86]. If a user is an active user in an SNS, the user would post content, transmit content, and contribute to the relationship. Each of the active behaviors is a reflection of users’ overall activity. Second, all the correlations between the four first-order factors are around 0.5 (as shown in Table 7), which is relatively high. Internal consistency or reliability is important in reflective measures, USERS’ ACTIVE BEHAVIOR ON SNSS CC1 CC2 CC3 CT1 .761 .828 Content Creation .786 CT2 IRC1 IRC2 IRC4 Content Transmission Overall Active Behavior on an SNS .661 .610 .844 .883 Individual Relationship Contribution .856 .783 IRC5 GRC1 GRC2 GRC3 GRC4 .730 .829 .909 IRC3 .815 .867 .925 CT3 231 .776 .725 .771 .775 Group Relationship Contribution .843 GRC5 Figure 3. Second-Order Factor Measurement Model implying that all first-order factors are measuring the same phenomenon, and if the value for one of the measures changes, then the other values should also move in the same direction [86]. This demonstrates that the four factors are reflecting the same thing to a large extent [13, 86]. With formative constructs, measures need not covary. In fact, strong intercorrelations among formative measures is an indication of multicollinearity. Third, to further test whether the second-order construct can be treated as a formative construct, we calculated the level of collinearity of the four first-order factors. As suggested by Cenfetelli and Bassellier [17], eigenvalues of the correlation matrix of predictors that significantly depart from 1.00 indicate mulitcollinearity. The results (eigenvalues are .048, .047, .040, and .025) demonstrate that multicollinearity exists among these factors, which is a characteristic of a reflective construct. Thus, the overall active behavior in an SNS can be considered to be a reflective construct. We used two different criteria to compare the second-order factor model with the first-order factor model. First, we compared the statistics of the two models [99]. The fit indices of the second-order model (χ2/df = 2.802; CFI = .965; GFI = .932; AGFI = .908; NFI = .947; TLI = .958; RMSEA = .062) are similar to that of the first-order model. For this criterion, the second-order factor model is preferred over the first-order factor model as it explains the covariance among the first-order factors more parsimoniously [99]. Second, we computed the target coefficient to compare the two models. Marsh and Hocevar [67] suggested that the efficacy of second-order 232 CHEN, LU, CHAU, AND GUPTA models should be assessed by examining the target (T) coefficient [T = χ2 (baseline model)/χ2 (alternative model)]. When the target coefficient is close to its upper bound of 1.0, the second-order factor model is preferred over the first-order factor model [101]. The value of the target coefficient value in our case is 0.999, which is very close to the upper limit of 1.0. This suggests that the second-order factor model is superior to the first-order factor model. From these two tests, we conclude that the second-order factor model is a better measurement model in operationalizing users’ overall active behavior on an SNS. An Empirical Use of the Measurement Model AFTER TESTING THE VALIDITY OF OUR MEASUREMENT MODEL, we conducted empirical tests using commitment theory to further examine the model to understand overall active behavior in an SNS. Commitment Theory and Hypotheses Development Commitment theory was developed by Allen and Meyer [3] in the domain of organizational behavior. It explains employees’ psychological binding to the workplace or specific activities that benefit the organization [69]. According to Meyer and Herscovitch, commitment is a stabilizing or obliging force that gives direction to behavior (e.g., restricts freedom, binds a person to a course of action) [69]. Commitment can influence behavior independently, even in the absence of exchange-based forms of motivation and target-relevant positive attitudes, and may lead to persistence in a course of action, even in the face of conflicting motives or attitudes [58, 69]. The notion of commitment has been used to examine users’ adoption and postadoption behavior in the context of online services. Li et al. [58], for example, identified affective commitment and calculative commitment to explain the continuance intention of online services. Li et al. [58] further suggested that trust and the quality of alternatives are antecedents to these two types of commitment in the web service context. Kim and Son [54] explained the postadoption behavior of online portal services by proposing a dedication-constraint dual model. In particular, the model predicts that two contrasting mechanisms of commitment—dedication and constraint—are the main drivers of postadoption phenomena (i.e., consumers’ postadoption reactions to online services, such as their beliefs, attitudes, intentions, and behaviors). Building on this dedication-constraint framework [54], Zhou et al. [113] integrated the concepts of affective and calculative commitment to represent two distinctive commitment mechanisms and identified an encompassing set of antecedents of commitment specific to the social virtual world service context. Although these studies are useful for predicting online services continuance in general, they do not provide adequate insights into users’ overall active behavior in SNSs. USERS’ ACTIVE BEHAVIOR ON SNSS 233 Allen and Meyer [3] identified three components of commitment that reflect three distinguishable themes, namely, affective attachment to the target (affective commitment), perceived cost of leaving (continuance commitment), and obligation to act (normative commitment). Affective commitment refers to the psychological state of a user demonstrating an affective and emotional attachment to the service. Continuance commitment (also known as calculative commitment) occurs when the user determines that the costs associated with terminating use of a service or switching to another one are too high [58]. Normative commitment, understood as a sense of moral obligation to pursue a course of action [69], alludes to an obligation in terms of justice and duty. In this study, we define affective commitment as “users’ affective and emotional attachment to their active behaviors on an SNS.” The mind-set characterizing affective commitment is desire: individuals with a strong affective commitment want to pursue a course of action that is relevant to their target [69]. Aristotle explained the reasons or aims for specific human actions, arguing that the concept of the good is understood as the goal, or the end, of the action [40]. Although there are many goods that we human beings pursue in our actions—such as friendship, pleasure, virtue, honor, and wealth—these goods can be hierarchically ordered [40]. The affective dimension of commitment moves into the arena of enjoyment, of feelings and desires, which is the same as the attractiveness of pleasant goods described by Aristotle. Pleasant goods can be identified with the affective dimension of commitment, in which the world of emotions explains the attachment to courses of action such as higher priority to community goals, means, or people. Affective commitment also suggests that the user has positive attitudes toward the user’s past active behaviors in the SNS, which is generally associated with affection, happiness, and pleasure [49]. In the context of SNSs, desire or the attractiveness of pleasant goods can be induced in a user by the user’s (1) becoming involved (intrinsically motivated, absorbed) in a course of action, (2) recognizing the value-relevance of the pursuit of the course of action, or (3) deriving his or her identity from association with a community [69]. In addition, human beings need social interactions to satisfy their social needs of belonging and support [68]. An SNS provides a platform whereby users can exchange support with one another. Active behavior in an SNS can help a person receive support from friends, which brings the person warmth. Such good experiences satisfy users in their social interactions with their friends and help fulfill the users’ social needs and produce affective attachment to active behavior in the SNS [58]. Thus, such psychological desire could explain users’ overall active behavior in an SNS, which leads to the following hypothesis: Hypothesis 1: Affective commitment is positively associated with the overall active behavior in an SNS. We define continuance commitment as “users’ recognition of the rewards and benefits associated with being active on an SNS.” It is characterized by the perception that it would be costly to discontinue a course of action. Such commitment occurs when a user determines that the cost associated with just lurking in an SNS or switching to another 234 CHEN, LU, CHAU, AND GUPTA site is too high, considering the user’s investments in the current site [58, 69]. Continuance commitment is, in fact, a kind of human action guided by the objective of external or useful goods, as described by Aristotle [as discussed in 40]. In the context of SNSs, users invest considerable time and effort in developing close interpersonal relationships with other members of the network, thus building their reputation. By posting contents or other acitve behaviors, they develop goodwill, trust, a sense of identity, and a reputation among their friends, which enhances the value that they derive from using the network [93, 104]. Relationships and individual user reputation are valuable and durable in social networks, and they are neither transferable nor easily replicable to other networks [104]. These investments constitute sunk costs, which are diminished or lost if the user does not behave actively in the specific SNS. Thus, such commitment may explain users’ overall active behavior on an SNS, leading to the following hypothesis: Hypothesis 2: Continuance commitment is positively associated with the overall active behavior in an SNS. We define normative commitment as “the obligation of a user to pursue active behavior in an SNS.” Normative commitment develops when an individual (1) has internalized a set of norms considered appropriate through socialization, or (2) is a recipient of benefits and experiences the need to reciprocate [69]. Normative commitment is undoubtedly connected with the moral dimension, or moral good, as described by Aristotle. This kind of good refers to desirable traits of character, to human excellence or moral virtues. One of the moral virtues is rational evaluation of the conscience about what is right or wrong, just or unjust, fair or unfair, and not only a feeling [40]. Another moral virtue is sense of duty, or responsibility, or moral accountability—the willingness to account for one’s actions [40]. In an SNS context, a user may feel an obligation to behave actively when the user benefits from the online actions of friends, or when individuals around the user are very active. To do this, the user can accept feedback from others and avoid being isolated from friends. And a user should feel guilty when the user fails to conduct active behavior regularly as expected by the user’s circle [40, 113]. Thus, such psychological commitment is likely to drive users’ active behavior on an SNS, leading to our third hypothesis: Hypothesis 3: Normative commitment is positively associated with the overall active behavior in an SNS. To develop a rigorous model, we specified various population characteristics as control variables: (1) age, (2) gender, (3) identity (student or nonstudent), and (4) relationship status (single, in love, or married). Nosko et al. [77] indicated that users’ age and relationship status significantly influence their disclosure behavior on Facebook. Disclosure behavior decreases with age. Older individuals may be more cautious when behaving online. Individuals who are searching for romantic relationships may use the online medium as a way to self-present or to advertise themselves to potential dating partners [77]. Using a combination of data mining and content analysis, Thelwall et al. [103] found that males and females behave differently in posting comments on MySpace. USERS’ ACTIVE BEHAVIOR ON SNSS 235 As noted previously, Renren is an SNS that was originally designed mainly for students in universities, and then expanded to other populations in the society. However, students who have leisure time may behave more actively than individuals at the workplace. Therefore, to examine the relationship between the three components of commitment and overall active behavior of a user on an SNS, we control for these four factors. Methodology Survey Administration We tested our model using data collected from a large sample survey. Our sampling frame was the users of Renren (http://www.renren.com). Overall, 1,457 participants completed the questionnaire. A pilot test of thirty subjects suggested that the questionnaire required at least ten minutes for completion. After deleting those questionnaires with missing values and those completed in less than ten minutes, we were left with 1,242 valid questionnaires. The demographics of the respondents are summarized in Table 9. We also conducted a difference test between the demographic features of the current study and the large-scale national survey about SNS users in China [28]. Our results indicate that the two populations were similar in terms of demographic characteristics. Similar to the results of difference test in the measurement model development study, only the identity feature showed significant difference. Table 9. Descriptive Statistics of Survey Respondents Category Gender Age Education Identity Relationship status Items Male Female ≤ 19 20–29 ≥ 30 High school or below Junior college Undergraduate Graduate or above Students Nonstudents Single Just in love Married Sample (N = 1,242) CNNIC sample Frequency Percentage Percentage 598 644 92 1,072 78 123 48.1 51.9 7.4 86.3 6.3 9.9 53.7 46.3 29.0 56.8 14.2 7.2 362 687 70 29.1 55.3 5.6 37.4 42.7 12.6 586 656 607 440 195 47.2 52.8 48.9 35.4 15.7 Chi-square differences χ2(1) = .720 (p = .396) χ2(2) = 3.524 (p = .061) χ2(3) = 5.547 (p = .136) 26 χ2(1) = 9.514 (p = .002) 74 There are no data about participants’ relationship status in the CNNIC’s survey in 2012. 236 CHEN, LU, CHAU, AND GUPTA Measurement The overall active behavior of a user on an SNS was operationalized as a secondorder construct with four reflective first-order factors (creation, content transmission, group relationship contribution, individual relationship contribution). All four of these factors were measured using multiple-item scales obtained from the study of measurement model development reported in this paper. A seven-point scale ranging from 1 (never) to 7 (very frequently) was used to rate participants’ frequency of performing these behaviors. Affective commitment, continuance commitment, and normative commitment were measured by adapting scales from Li et al. [58] and Fullerton [36] to fit our research context. The measures used a seven-point scale ranging from 1 (strongly disagree) to 7 (strongly agree). The items correlated with these three components of commitment are presented in Table 10. Results We adopted structural equation modeling (SEM) to perform data analysis. We used the two-step approach proposed by Anderson and Gerbing [4], in which first a valid and reliable measurement is established, followed by testing of the structural model. Measurement Model We examined the measurement model for validity and reliability. Reliability was assessed based on Cronbach’s alpha and composite reliability scores. As shown in Table 11, Cronbach’s alpha and composite reliability estimates of all constructs exceeded the recommended threshold value of 0.7, indicating adequate construct reliability. Convergent validity was confirmed by examining the AVE and the factor loading of the indicators. A confirmatory factor analysis was employed to compute the factor loadings. Table 11 shows that the factor loadings range from 0.663 to Table 10. Measurement Items of Three Components of Commitment Latent variable Affective commitment Continuance commitment Normative commitment Items I feel emotionally attached to Renren. Renren has a great deal of personal meaning for me. I feel a strong sense of identification with Renren. It would be very hard for me to be inactive on Renren right now even if I wanted to. My life would be disrupted if I lurked on Renren. It would be too costly for me to lurk on Renren right now. I feel obligated to be active on Renren. Given all the things my friends and we had done for each other on Renren, I feel I ought to be active on Renren. I don’t feel it is right to lurk on Renren. USERS’ ACTIVE BEHAVIOR ON SNSS 237 Table 11. Measurement Model Statistics Construct Indicator Factor loading Cronbach’s alpha Content creation Content transmission Group relationship contribution Individual relationship contribution Affective commitment Continuance commitment Normative commitment CC1 CC2 CC3 CT1 CT2 CT3 GRC1 GRC2 GRC3 GRC4 GRC5 IRC1 IRC2 IRC3 IRC4 IRC5 AC1 AC2 AC3 CCO1 CCO2 CCO3 NC1 NC2 NC3 .663 .852 .750 .817 .863 .777 .727 .704 .765 .811 .789 .665 .891 .933 .838 .803 .809 .886 .819 .794 .847 .838 .848 .893 .877 CR AVE .789 .877 .703 .857 .913 .778 .871 .906 .659 .918 .939 .756 .874 .923 .799 .864 .918 .788 .905 .941 .841 Notes: All the boldface factor loadings are significant at the 0.001 level. 0.933, which are all significant at p = 0.001. The AVE values range from 0.659 to 0.841, thus displaying convergent validity. Discriminant validity was assessed using three methods. First, as seen in Table 12, all the diagonal elements in boldface (the square root of the AVE) were found to be Table 12. Construct Correlations and Discriminant Validity Constructs CC CT GRC IRC AC CCO NC CC CT GRC IRC AC CCO NC .838 .610 .508 .466 .411 .361 .323 .882 .535 .497 .372 .369 .270 .812 .440 .357 .375 .343 .869 .347 .231 .216 .894 .633 .625 .888 .695 .917 Note: Diagonal elements in boldface are the square root of the average variance extracted. 238 CHEN, LU, CHAU, AND GUPTA greater than any other corresponding rows or column entries (the interconstruct correlation coefficients). Second, we also assessed the factor loading and crossloading. The results (Table 13) demonstrate that each indicator had a higher loading on its intended construct than on any other construct. Third, for each pair of factors, we compared the χ2 value for the baseline model with the constraint model (by constraining their correlation as 1). The results of these tests show significant differences in each case, suggesting that none of the twenty-one pairs of constructs could be merged as one construct (Table 14). Thus, based on these tests, our model demonstrates strong discriminant validity. Because self-reported data from a single source were used, we measured the extent of common methods bias using two analyses. First, a Harman’s single-factor test was conducted by entering all constructs in an unrotated principal component analysis and examining the resultant variance [43]. The results indicated the variance Table 13. Factor Loading and Cross-Loading 1 CC1 CC2 CC3 CT1 CT2 CT3 GRC1 GRC2 GRC3 GRC4 GRC5 IRC1 IRC2 IRC3 IRC4 IRC5 AC1 AC2 AC3 CCO1 CCO2 CCO3 NC1 NC2 NC3 Eigenvalue Variance % Cumulative % 2 3 4 5 6 7 .103 .300 .222 .283 .212 .214 -.006 .181 .184 .290 .205 .700 .861 .882 .851 .827 .103 .123 .222 .080 .051 .091 .025 .108 .066 .341 .165 .129 .222 .231 .269 .714 .760 .786 .715 .780 .193 .189 .172 .116 .109 .114 .125 .130 .149 .159 .120 .159 .119 .123 .162 .050 .066 .039 .050 .103 .094 -.015 .090 .167 .133 .033 .066 .068 .051 .034 .234 .263 .292 .250 .289 .409 .762 .846 .833 .061 .152 .146 .179 .090 .037 .001 .141 .087 .110 .073 .019 .103 .095 .106 .131 .724 .816 .782 .295 .185 .258 .215 .243 .264 .105 .066 .102 .049 .135 .152 .227 .022 .088 .024 .113 .116 .030 .035 .026 .025 .331 .229 .174 .743 .818 .700 .386 .233 .233 .096 .299 .253 .736 .816 .755 .138 .159 .135 .142 .157 .108 .123 .132 .153 .170 .096 .111 .097 .123 .137 .086 .060 .058 .059 .736 .713 .742 .232 .209 .175 .214 .131 .138 .122 .043 .104 .067 .108 .162 .150 .189 .133 .053 .113 .083 .086 .085 .105 .080 3.857 15.427 15.427 3.010 12.041 27.467 2.834 11.337 38.804 2.736 10.945 49.749 2.291 9.163 58.912 1.903 7.612 66.524 1.781 7.124 73.618 USERS’ ACTIVE BEHAVIOR ON SNSS 239 Table 14. Pairwise Discriminant Validity Analyses Two-factor combinations for constrained measurement models Content creation & Content transmission Content creation & Individual relationship contribution Content creation & Group relationship contribution Content creation & Affective commitment Content creation & Continuance commitment Content creation & Normative commitment Content transmission & Individual relationship contribution Content transmission & Group relationship contribution Content transmission & Affective commitment Content transmission & Continuance commitment Content transmission & Normative commitment Individual relationship contribution & Group relationship contribution Individual relationship contribution & Affective commitment Individual relationship contribution & Continuance commitment Individual relationship contribution & Normative commitment Group relationship contribution & Affective commitment Group relationship contribution & Continuance commitment Group relationship contribution & Normative commitment Affective commitment & Continuance commitment Affective commitment & Normative commitment Continuance commitment & Normative commitment χ2 χ2 difference 1,627.293 1,748.741 1,779.410 1,720.346 1,750.507 1,762.558 1,667.811 1,648.614 1,640.325 1,657.040 1,681.405 1,765.798 26.868*** 148.316*** 178.985*** 119.921*** 150.082*** 162.133*** 67.386*** 48.189*** 39.9*** 56.615*** 80.98*** 165.373*** 1,714.817 1,771.548 1,767.435 1,758.527 1,759.038 1,764.885 1,605.852 1,605.719 1,604.41 114.392*** 171.123*** 167.01*** 158.102*** 158.613*** 164.46*** 5.427* 5.294* 3.985* Notes: The unconstrained measurement model: χ2 (254) = 1,600.425. ***p ≤ .001; **p ≤ 0.01; *p ≤ 0.05. explained by the most significant factor is only 15.4 percent. Second, following Liang et al. [59], we included a common methods factor whose indicators included all the principal constructs’ indicators and calculated each indicator’s variances explained by the principal constructs and by the method. The average substantively explained variance of the indicators is 0.716, and the average method-based variance was 0.001. In addition, the principal variable loadings were all significant at the 0.001 level, whereas most common methods factor loadings were not significant. We thus concluded that common methods bias is not likely to be a problem in our data set. Structural Model Following the standard procedure of testing a structural model [4], we obtained the results and found that all model fit indices (χ2 = 930.195; df = 351; χ2/df = 2.650; CFI = 0.973; GFI = 0.950; AGFI = 0.938; NFI = 0.957; TLI = 0.969; RMSEA = 240 CHEN, LU, CHAU, AND GUPTA Affective commitment R2 = 33% .402*** Overall active behavior in an SNS .240*** Continuance commitment .832*** CC .849*** CT .717*** –.044 GRC Normative commitment .644*** –.053 Controls Age .007 –.013 –.095 Gender Identity IRC Relationship status Figure 4. Results of the Structural Model Notes: *** p < 0.001 (two-tailed); the insignificant (p > 0.05) paths are depicted with a dashed line. 0.036) were quite satisfactory. Figure 4 depicts the standardized path coefficients and explains endogenous variables’ variance for the structural model. As shown in Figure 4, two of the three hypotheses were supported. Specifically, affective commitment was found to be positively related to the overall active behavior on an SNS (b = 0.402, p < 0.001), thus supporting H1. Continuance commitment was also found to have a positive influence on the overall active behavior on an SNS (b = 0.240, p < 0.001), thus supporting H2. A positive relationship between normative commitment and the overall active behavior on an SNS (i.e., H3) was not supported, however. On comparing the path coefficients of the three components of commitment, we found that affective commitment was the most important driver of users’ overall active behavior on an SNS. Furthermore, all four control variables (i.e., age, gender, identity, relationship status) had no significant impact on the dependent variable. Overall, approximately one-third (33 percent) of the variance of dependent variables was explained by the antecedent variables. Because initial items were generated using a student sample in the Delphi study, we also compared the difference in active behaviors between students and nonstudents. We divided the data set into two subgroups according to the respondents’ identity. An independent-sample t-test was conducted to examine whether the means of active behaviors between the two subsets were significantly different. As shown in Table 15, only three out of sixteen active behaviors are significantly different according to users’ identity. These results support our use of a student sample in the Delphi study. To examine the different roles of three components of commitment on users’ active behaviors on SNSs, we further tested the paths from the commitments to each first-order construct of overall active behavior on an SNS. The results are shown in Figure 5. As expected, affective commitment has significant influence on all four dimensions of overall active behavior on an SNS. Continuance commitment has significant effect on three of the four dimensions (i.e., content creation, content transmission, and group relationship contribution). Normative commitment is .05026 .05811 .05715 .06643 .06984 .06727 .05194 .06227 .05845 .05883 .06778 .05712 .06463 .05817 .05843 .06453 3.6143 3.7918 3.9573 4.4744 4.6433 4.5717 Standard error 2.7133 3.8720 3.3123 4.1041 3.8515 3.1717 1.9812 3.4539 3.0051 3.2201 Means of samples Note: *p < 0.05, **p < 0.01, ***p < 0.001; ns = nonsignificant. Posting blogs/articles Changing/posting current status Posting photos/videos Sharing friends’ blogs Sharing friends’ photos Sharing or transmitting friends’ statuses Creating groups or public profiles Joining groups or public profiles Creating events and sending invitations Responding to invitations to participate in events from friends Interacting with groups Searching friends and sending application for adding friends Looking at personal information of friends Visiting friends’ profiles Looking at news about friends Looking at photos of friends Active behaviors Students (N = 586) 4.2332 4.4939 4.5671 4.5686 3.5460 3.8643 3.0198 3.7655 3.2759 4.0201 3.4634 3.2210 2.0555 3.3354 3.0473 3.3064 .05824 .05526 .05669 .05910 .06346 .05383 .04879 .05314 .05447 .06062 .06173 .06153 .05320 .05932 .05646 .05760 Standard error Nonstudents (N = 656) Means of samples Table 15. Comparison of Active Behaviors Between Students and Nonstudents ns ns *** ns ns ns –3.180 –.243 .935 .035 *** ns ns ns *** ns ns ns ns ns –4.369 1.899 .046 1.164 4.180 1.853 –1.333 1.378 –.518 –1.046 1.891 –.924 Significance level Differences t-value USERS’ ACTIVE BEHAVIOR ON SNSS 241 242 CHEN, LU, CHAU, AND GUPTA Affective Commitment Affective .320*** Commitment .319*** 2 2 R = 17% R = 19% Continuance .120*** Commitment Normative Content Continuance Creation Commitment .041 Normative Commitment Affective .159*** -.043 Commitment .186*** Commitment Affective 2 R = 17% .352*** Commitment Group Continuance .166*** Commitment Normative Commitment Content Transmission Relationship Contribution .108** 2 R = 14% Individual Continuance .008 Commitment Normative Relationship Contribution 0.022 Commitment Figure 5. Roles of the Three Components of Commitment on Users’ Active Behaviors Notes: ***p < 0.001 (two-tailed); the insignificant (p > 0.05) paths are depicted by dashed line. significantly associated only with group relationship contribution. These results explain why affective commitment is the most important driver of overall active behavior of users of an SNS. Continuance commitment plays only a moderate role, and the role of normative commitment is almost nonsignificant. Discussion THE RESULTS OF THIS STUDY PROVIDE SUPPORT TO the measurement model for use in exploring users’ overall active behavior on an SNS. The research highlights the driving role of three components of commitment on the overall active behavior in an SNS. First, affective commitment is the most important driver of users’ overall active behavior in an SNS. It may be the most important driver because the overall active behavior in an SNS is a multidimensional construct consisting of four factors, and affective commitment may correlate strongly with a wider range of these factors. Another explanation is that affective commitment is generally defined and operationalized more broadly than continuance and normative commitment [69]. When users want to engage in a course of action in an SNS because of attachment to, or desire USERS’ ACTIVE BEHAVIOR ON SNSS 243 for, that particular course of action, they are less sensitive to cues that potentially delimit their behavior. Rather, their mind-set directs attention to the intended outcome and thereby allows them to regulate their behavior to achieve that outcome [69]. In contrast, when users pursue a course of action to avoid costs, or out of obligation, they are more sensitive to conditions that define what is required or expected of them. Second, as expected, continuance commitment has significant influence on the overall active behavior in an SNS. This is consistent with the results of prior studies [58], which indicate that continuance commitment has a significant effect on the continuance of website use. Third, contrary to our expectations, the effect of normative commitment on overall active behavior of a user in an SNS was not significant. This is because normative commitment significantly influences only one of the four types of active behaviors, that is, group relationship contribution. Although the theory of social influence posits that if people around a user expect a particular kind of behavior that is being engaged in by most people around them, then the user feels obligated to behave in that manner [46], a few previous studies [3, 53, 58] have indicated that normative commitment has little effect on human behavior. One possible explanation for this contradiction is that SNSs are voluntary communities [12], in which users are free not to participate. This study further provides adequate evidence for usability and good performance of the instruments that were developed in the measurement model of this study. All the results of reliability and validity tests and the fit indices of the measurement model and the structural model were found to be satisfactory. This suggests that the final items retained in the measurement model development study can be used in an instrument for future research. Another interesting and somewhat suprising result should be specifically noted. Through the literature review and the Delphi study, we classified overall active behavior in an SNS into four categories: content creation, content transmission, relationship building, and relationship maintenance. However, in the measurement development study, the two dimensions related to relationship contribution—that is, relationship building and relationship maintenance—were segregated into individual relationship contribution and group relationship contribution. Three reasons can explain this inconsistency. First, the two types of relationships are primary to the relationship system (individual-individual and individual-group), and users behave differently in these two relationships [22]. In organizational theorists’ multilevel research, groups are often defined as collectives. A collective is “any interdependent and goal-directed combination of individuals, groups departments, organizations, or institutions” [71]. Individuals undertake different practices to deal with collective relationships as compared to personal relationships [71]. More important, individuals often belong to multiple teams concurrently, and different groups develop their own norms of communication [110], thus provoking members to behave differently in various groups in SNSs. Second, individuals form groups and participate in group activities in SNSs that fulfill their interests, whereas the relationships among 244 CHEN, LU, CHAU, AND GUPTA individuals in SNSs are primarily organized around people seeking social support and forming social capital, not around interests [12]. Third, from the perspective of SNS operators, there are multiple relationships in SNSs [5], and both individual relationships and group relationships are important resources for SNSs’ growth and survival. No matter how users build or maintain relationships, in practice they contribute relationship resources to the SNS. Because we did not detect the dimensions of individual relationship contribution and group relationship contribution from the literature review and the Delphi study, we deemed it prudent to identify the novel dimensions of users’ active behavior in an SNS from the measurement development study. Future researchers could more deeply examine a user’s individual and group behavior in an SNS. Contributions to Research This research offers three primary contributions to the existing body of knowledge about users’ active behavior in an SNS. First, the results contribute to research on social media. We identify one of the research opportunities by providing insights into the complex human behaviors in SNSs. The thirty-four infrastructural items provide insights into various behaviors that users perform in SNSs, some of which have been examined in previous studies [35]. And the classification of users’ active behavior in an SNS (i.e., content creation, content transmission, and individual and group relationship building and maintenance) gives us new understanding about the essence and contributions of active users in SNSs. Second, the current study complements the existing research on cocreation. Cocreation is the participation of consumers along with producers in the creation of value in the marketplace. Zwass [114] categorized cocreation as sponsored and autonomous. Previous research [20, 88] has investigated company-sponsored cocreation. Our research focuses on a specific form of autonomous cocreation in the SNS context. Zwass [114] classified cocreation into four entity components capturing the most salient aspects of cocreation: (1) cocreators; (2) process; (3) characteristics of the task to be accomplished; and (4) cocreated value received by cocreating communities or individuals. In our framework, the task is specified as contributing to content and relationships in SNSs. The cocreators are active users in SNSs who cocreate through their active behavior, and the cocreated value is measured by active users’ contibution level. Thus, the results contribute to our understanding of users’ cocreation pattern in the specific SNS context. Third, our study contributes to research in social commerce. The proliferation of social media has transformed consumer behavior. The social feature of social media can improve customers’ enjoyment experience and improve their decision quality [42, 60]. In the context of SNSs, the content creation behavior and content transmission behavior contribute to social knowledge, which provides opportunity for customers’ social learning. And the relationships embedded in the SNSs facilitate social interaction and provide an environment for social commerce. Within this USERS’ ACTIVE BEHAVIOR ON SNSS 245 environment, customers can access social knowledge and experiences by interacting in forums and communities, by browsing ratings and reviews posted by others, or by considering others’ recommendations [48, 50]. All of these commercial activities can only be realized by conducting the basic social activities in SNSs. The various active behaviors identified in this research capture the most important social activities performed in an SNS that provide fundamental insight into social commerce behavior. Another contribution of this paper is the development of a comprehensive measure of overall active behavior in an SNS. This paper provides a theoretically sound measurement instrument that addresses the complex characteristics of users’ active behavior in an SNS. This measurement instrument should be useful for future studies of SNSs. The existence of a validated baseline measure would be a useful starting point and enhance the quality of measurement of specific aspects of users’ active behavior. Of course, the validity of a measure cannot be fully established on the basis of a single study. Validation of measures is an ongoing process that requires assessment of measurement properties over a variety of studies in similar and diverse contexts [29]. Development of an alternative means of assessing users’ active behavior in an SNS would be useful for future research. Last, this study contributes by demonstrating that commitment theory is relevant for understanding the mind-set driving users’ overall active behavior in an SNS. This commitment perspective has implications for both human behavior and website management strategies in the SNS domain. First, the study has presented a different commitment perspective on online behavior research. In contrast to the dominant paradigms, such as TAM [31] and social capital theory [73], this study is one of the first to introduce commitment theory to explain users’ overall active behavior in an SNS. Our commitment-based research model provides a useful framework for future studies on online human behavior. A comparative study or an integrated study of commitment theories and models such as TAM and social capital theory could be of interest to the research community. Second, the driving role of affective and continuance commitment on users’ active behavior in an SNS provides new insights. This study also shows the different roles of the three components of commitment. It is important to consider the different dimensions of commitment rather than confining its conceptualization to a unidimensional construct called organizational commitment [47], or just commitment [91]. Our study provides evidence for the feasibility of investigating commitment as a multidimensional construct in the SNS context. Future research can apply commitment theory to other aspects of website management. Implications for Practice The results of our study provide practitioners with a set of interesting insights into enhancing users’ active behavior in an SNS. They also suggest strategies that SNS providers should focus on to incerease users’ affective and continuance commitment. 246 CHEN, LU, CHAU, AND GUPTA First, some personalization features can improve affective commitment. To build social and psychological bonds with an SNS, SNS designers can incorporate features that increase the sense of “personal care,” “belongingness,” and “community” for online customers [58]. To enhance emotional attachment, site managers should encourage users to participate in activities together with their friends and enhance connectedness among them. To develop these connections, the SNS design could incorporate one-to-one personal connections between friends enabled by real-time communication technologies such as instant messaging. Second, increased investment should lead to a higher continuance commitment [58], because the cost of lurking on the SNS has increased and the benefits of being active have also increased. For instance, users may reveal privacy information on the SNS and spend time to communicate with friends through through the SNS. Managers can use personalization technology so that users can share personal data with websites and friends. The SNS design can develop attractive applications or games to increase users’ time on the website. The list of thirty-four active behaviors identified in the Delphi study provide useful information about users’ various behaviors. Given the classification of the active behaviors based on their contribution to the sites, we recommend that managers diagnose the weaknesses of their websites and take suitable strategies to improve users’ specific contributions. Recent research has demonstrated that content and relationship are the main contributions of SNS users [61]. Therefore, firms must take these two contributions into account when designing their websites, and different design principles should be followed to enhance the four aspects of user contributions (content creation, content transmission, relationship building, and relationship maintenance). These identified behaviors are essential for the growth of social relationships, accumulation of user-generated content, and increased volume of site visits and traffic [21], all of which are imperative for increased market capitalization and revenues [16]. With the first-order and second-order measurement models, more comprehensive understanding about the overall active behavior in SNSs will provide managers with new insights, thus allowing them to develop more precise strategies to facilitate users’ participation in various activities offered on the sites. Because users behave differently in contributing to individual and group relationships, managers should utilize different strategies and design principles for individual applications and group applications. Limitations and Future Research We acknowledge the limitations of our study. First, we did not include SNS operators as panelists in the Delphi study. Although our academic panelist and active user panelist structure helped us obtain sufficient perspectives on our study, including SNS operators as panelists might have given us a broader perspective about users’ active behavior on SNSs. USERS’ ACTIVE BEHAVIOR ON SNSS 247 Second, as with most other empirical studies, the spectrum of respondents in our online survey limits generalizability. Even though the samples include a range of individuals representing different demographic groups of Internet users, the subjects were all users of Renren.com in China. The differences between Western and nonWestern culture may limit the external validity of the research findings [52]. One should be cautious in generalizing the model to other types of SNSs and users in other countries. Besides, the identity feature of the respondents in this study showed significant difference from the sample of China Internet Network Information Center (CNNIC) [28]. Although our sample is representative of the entire active population of Renren users to some extent, the large proportion of student responses probably generated some bias. Future research can employ data from a broader sample to observe users’ actual behaviors. This research focuses only on developing a classification, a measurement model, and a simple predicting model of users’ overall active behavior on an SNS. Future research could explore other factors driving users’ overall active behavior and investigate the outcomes of various active behaviors. Specifically, it would be interesting to examine the association between social relationship and social content creation behaviors or the relationship between the four dimensions of active behavior and human well-being. This research indicates that identifying different kinds of active behaviors is important. Specifically, diferent kinds of active behaviors may play different roles in affecting people’s daily lives, in structuring cocreation patterns, and in leading to social commerce behavior. Future studies might test the roles of the four categories of active behaviors identified in the Delphi study. Finally, commitment is simply a psychological mind-set that drives human behavior [69]. We did not investigate the antecedents producing this mind-set. Although factors driving the three types of commitment have been investigated in other domains, such as organizations [3], workplaces [69], and marketing channels [53], it may not be the same situation for this emerging online service. Therefore, researchers can explore antecedents driving users’ commitment to active behavior on an SNS. Conclusion DESPITE THE IMPORTANT ROLE OF ACTIVE BEHAVIORS IN SNSs, extant research on this topic has mainly focused on adoption behavior and single components of active behavior. To further examine this important yet underexplored issue, we conducted a Delphi study, a measurement development study, and an empirical examination of the measurement model study. Our classification framework and the first-order and second-order measurement models were found to be useful in understanding the overall active behavior of SNS users. The empirical study applied the commitment theory in the SNS context, thus generating a few interesting insights. The findings 248 CHEN, LU, CHAU, AND GUPTA have important implications for practice as they elaborate upon managing and stimulating users’ active behavior on an SNS. Acknowledgments: This work was supported by grants from the NSFC (71332001) and Prof. Yaobin Lu is the corresponding author of this paper. REFERENCES 1. Acquisti, A., and Gross, R. Imagined communities: Awareness, information sharing, and privacy on the Facebook. Privacy Enhancing Technologies: 6th International Workshop, Cambridge, UK, Springer, 2006, 36–58. 2. Agnihotri, R.; Kothandaraman, P.; Kashyap, R.; and Singh, R. Bringing “social” into sales: The impact of salespeople’s social media use on service behaviors and value creation. Journal of Personal Selling and Sales Management, 32, 3 (2012), 333–348. 3. Allen, N.J., and Meyer, J.P. The measurement and antecedents of affective, continuance and normative commitment to the organization. Journal of Occupational Psychology, 63, 1 (1990), 1–18. 4. Anderson, J.C., and Gerbing, D.W. Structural equation modeling in practice: A review and recommended two-step approach. Psychological Bulletin, 103, 3 (1988), 411–423. 5. Ansari, A.; Koenigsberg, O.; and Stahl, F. Modeling multiple relationships in social networks. Journal of Marketing Research, 48, 4 (2011), 713–728. 6. Antheunis, M.L.; Valkenburg, P.M.; and Peter, J. Getting acquainted through social network sites: Testing a model of online uncertainty reduction and social attraction. Computers in Human Behavior, 26, 1 (2010), 100–109. 7. Baek, Y.M.; Bae, Y.; and Jang, H. Social and parasocial relationships on social network sites and their differential relationships with users’ psychological well-being. Cyberpsychology, Behavior, and Social Networking, 16, 7 (2013), 512–517. 8. Barclay, D.; Higgins, C.; and Thompson, R. The partial least squares (PLS) approach to causal modeling: Personal computer adoption and use as an illustration. Technology Studies, 2, 2 (1995), 285–309. 9. Benevenuto, F.; Rodrigues, T.; Cha, M.; and Almeida, V. Characterizing user behavior in online social networks. In Y. Chen, A. Kuzmanovic, and F. Bustamante (eds.), Proceedings of the 9th ACM SIGCOMM Conference: Internet Measurement Conference. Chicago, IL: ACM Press, 2009, pp. 49–62. 10. Benlian, A.; Koufaris, M.; and Hess, T. Service quality in software-as-a-service: Developing the SaaS-Qual measure and examining its role in usage continuance. Journal of Management Information Systems, 28, 3 (Winter 2011), 85–126. 11. Bernoff, J., and Li, C. Groundswell: Winning in a World Transformed by Social Technologies. Boston: Harvard Business School Publishing, 2008. 12. Boyd, D.M., and Ellison, N.B. Social network sites: Definition, history, and scholarship. Journal of Computer-Mediated Communication, 13, 1 (2008), 210–230. 13. Bruhn, M.; Georgi, D.; and Hadwich, K. Customer equity management as formative second-order construct. Journal of Business Research, 61, 12 (2008), 1292–1301. 14. Bucklin, R.E., and Sismeiro, C. Click here for Internet insight: Advances in clickstream data analysis in marketing. Journal of Interactive Marketing, 23, 1 (2009), 35–48. 15. Butler, B.S. Membership size, communication activity, and sustainability: A resourcebased model of online social structures. Information Systems Research, 12, 4 (2001), 346–362. 16. Carroll, E. Success Factors of Online Social Networks. Chapel Hill: University of North Carolina Press, 2007 17. Cenfetelli, R.T., and Bassellier, G. Interpretation of formative measurement in information systems research. MIS Quarterly, 33, 4 (2009), 689–707. 18. Chang, Y.P., and Zhu, D.H. The role of perceived social capital and flow experience in building users’ continuance intention to social networking sites in China. Computers in Human Behavior, 28, 3 (2012), 995–1001. USERS’ ACTIVE BEHAVIOR ON SNSS 249 19. Chen, A.; Lu, Y.; Wang, B.; Zhao, L.; and Li, M. What drives content creation behavior on SNSs? A commitment perspective. Journal of Business Research, 66, 12 (2013), 2529–2535. 20. Chen, L.; Marsden, J.R.; and Zhang, Z. Theory and analysis of company-sponsored value co-creation. Journal of Management Information Systems, 29, 2 (Fall 2012), 141–172. 21. Chen, R. Member use of social networking sites—An empirical examination. Decision Support Systems, 54, 3 (2013), 1219–1227. 22. Cheung, C.M.K., and Lee, M.K.O. A theoretical model of intentional social action in online social networks. Decision Support Systems, 49, 1 (2010), 24–30. 23. Cheung, C.M.K.; Chiu, P.Y.; and Lee, M.K.O. Online social networks: Why do students use facebook? Computers in Human Behavior, 27, 4 (2011), 1337–1343. 24. Chin, W.W.; Gopal, A.; and Salisbury, W.D. Advancing the theory of adaptive structuration: The development of a scale to measure faithfulness of appropriation. Information Systems Research, 8, 4 (1997), 342–367. 25. Chiu, C.M.; Hsu, M.H.; and Wang, E.T.G. Understanding knowledge sharing in virtual communities: An integration of social capital and social cognitive theories. Decision Support Systems, 42, 3 (2006), 1872–1888. 26. Chiu, C.M.; Cheng, H.L.; Huang, H.Y.; and Chen, C.F. Exploring individuals’ subjective well-being and loyalty towards social network sites from the perspective of network externalities: The Facebook case. International Journal of Information Management, 33, 3 (2013), 539–552. 27. Churchill Jr., G.A. A paradigm for developing better measures of marketing constructs. Journal of Marketing Research, 16, 1 (1979), 64–73. 28. CNNIC [China Internet Network Information Center]. Report on Social Network Applications of Internet Users in China. (2012). Available from www.cnnic.net.cn/hlwfzyj/ hlwxzbg/sqbg/201209/t20120903_36006.htm. 29. Compeau, D.R., and Higgins, C.A. Computer self-efficacy: Development of a measure and initial test. MIS Quarterly, 19, 2 (1995), 189–211. 30. Daugherty, T.; Eastin, M.S.; and Bright, L. Exploring consumer motivations for creating user-generated content. Journal of Interactive Advertising, 8, 2 (2008), 1–24. 31. Davis, F.D. Perceived usefulness, perceived ease of use, and user acceptance of information technology. MIS Quarterly, 13, 3 (1989), 319–340. 32. English, J.M., and Kernan, G.L. The prediction of air travel and aircraft technology to the year 2000 using the Delphi method. Transportation Research, 10, 1 (1976), 1–8. 33. Fang, Y., and Neufeld, D. Understanding sustained participation in open source software projects. Journal of Management Information Systems, 25, 4 (Spring 2009), 9–50. 34. Fornell, C., and Larcker, D.F. Evaluating structural equation models with unobservable variables and measurement error. Journal of Marketing Research, 18, 1 (1981), 39–50. 35. Foster, M.K.; Francescucci, A.; and West, B.C. Why users participate in online social networks. International Journal of E-Business Management, 4, 1 (2010), 3–19. 36. Fullerton, G. Creating advocates: The roles of satisfaction, trust and commitment. Journal of Retailing and Consumer Services, 18, 1 (2011), 92–100. 37. Garg, R.; Smith, M.D.; and Telang, R. Measuring information diffusion in an online community. Journal of Management Information Systems, 28, 2 (Fall 2011), 11–38. 38. Ghose, A., and Ipeirotis, P. The EconoMining project at NYU: Studying the economic value of user-generated content on the Internet. Journal of Revenue & Pricing Management, 8, 2 (2009), 241–246. 39. Goldenberg, J.; Oestreicher-Singer, G. and Reichman, S. The quest for content: How user-generated links can facilitate online exploration. Journal of Marketing Research, 49, 4 (2012), 452–468. 40. González, T.F., and Guillén, M. Organizational commitment: A proposal for a wider ethical conceptualization of ‘normative commitment. Journal of Business Ethics, 78, 3 (2008), 401–414. 41. Greenhow, C., and Burton, L. Help from my “friends”: Social capital in the social network sites of low-income students. Journal of Educational Computing Research, 45, 2 (2011), 223–245. 250 CHEN, LU, CHAU, AND GUPTA 42. Hajli, M. An integrated model for e-commerce adoption at the customer level with the impact of social commerce. International Journal of Information Science and Management, 16, Special Issue, 2012 ECDC(2012), 77–97. 43. Harman, H.H. Modern Factor Analysis. Chicago: University of Chicago Press, 1976 44. Heinonen, K. Consumer activity in social media: Managerial approaches to consumers’ social media behavior. Journal of Consumer Behaviour, 10, 6 (2011), 356–364. 45. Hogg, M.A. A social identity theory of leadership. Personality and Social Psychology Review, 5, 3 (2001), 184–200. 46. Hsu, C.L., and Lu, H.P. Why do people play on-line games? An extended TAM with social influences and flow experience. Information & Management, 41, 7 (2004), 853–868. 47. Hsu, C.-P.; Chang, C.-W.; Huang, H.-C.; and Chiang, C.-Y. The relationships among social capital, organisational commitment and customer-oriented prosocial behaviour of hospital nurses. Journal of Clinical Nursing, 20, 9/10 (2011), 1383–1392. 48. Huang, Z., and Benyoucef, M. From e-commerce to social commerce: A close look at design features. Electronic Commerce Research and Applications, 12, 4 (2012), 246–259. 49. Jaros, S.J., Jermier, J.M.; Koehler, J.W.; and Sincich, T. Effects of continuance, affective, and moral commitment on the withdrawal process: An evaluation of eight structural equation models. Academy of Management Journal, 36, 5 (1993), 951–995. 50. Jensen, M.L.; Averbeck, J.M.; Zhang, Z.; and Wright, K.B. Credibility of Anonymous Online Product Reviews: A Language Expectancy Perspective. Journal of Management Information Systems, 30, 1 (Summer 2013), 293–324. 51. Jia, Y.; Zhao, Y.; and Lin, Y. Effects of system characteristics on users’ self-disclosure in social networking sites. Proceedings of the Seventh International Conference on Information Technology. New York: IEEE Press, 2010, pp. 529–533. 52. Kim, A.J. Community building on the Web: Secret strategies for successful online communities. Boston: Addison-Wesley Longman, 2000. 53. Kim, S.K.; Hibbard, J.D.; and Swain, S.D. Commitment in marketing channels: Mitigator or aggravator of the effects of destructive acts? Journal of Retailing, 87, 4 (2011), 521–539. 54. Kim, S.S., and Son, J.-Y. Out of dedication or constraint? A dual model of postadoption phenomena and its empirical test in the context of online services. MIS Quarterly, 33, 1 (2009), 49–70. 55. Kim, Y.; Sohn, D.; and Choi, S.M. Cultural difference in motivations for using social network sites: A comparative study of American and Korean college students. Computers in Human Behavior, 27, 1 (2011), 365–372. 56. Kuan, K.K.Y.; Zhong, Y.; and Chau, P.Y.K. Informational and normative social influence in group-buying: Evidence from self-reported and EEG data. Journal of Management Information Systems, 30, 4 (Spring 2014), 151–178. 57. Lee, F.S.; Vogel, D.; and Limayem, M. Virtual community informatics: A review and research agenda. Journal of Information Technology Theory and Application, 5, 1 (2003), 47–61. 58. Li, D.; Browne, G.J.; and Chau, P.Y.K. An empirical investigation of Web site use using a commitment-based model. Decision Sciences, 37, 3 (2006), 427–444. 59. Liang, H.; Saraf, N.; Hu, Q.; and Xue, Y. Assimilation of enterprise systems: The effect of institutional pressures and the mediating role of top management. MIS Quarterly, 31, 1 (2007), 59–87. 60. Liang, T.-P., and Turban, E. Introduction to the Special Issue: Social commerce: A research framework for social commerce. International Journal of Electronic Commerce, 16, 2 (Winter 2011–12), 5–13. 61. Liang, T.-P; Ho, Y.-T.; Li, Y.-W.; and Turban, E. What drives social commerce: The role of social support and relationship quality. International Journal of Electronic Commerce, 16, 2 (Winter 2011–12), 69–90. 62. Liu, H.; Shi, J.; Liu, Y.; and Sheng, Z. The moderating role of attachment anxiety on social network site use intensity and social capital. Psychological Reports, 112, 1 (2013), 252–265. 63. Lu, H.P. and K.L. Hsiao, The influence of extro/introversion on the intention to pay for social networking sites. Information & Management, 47, 3 (2010), 150–157. USERS’ ACTIVE BEHAVIOR ON SNSS 251 64. Lu, Y.; Zhao, L.; and Wang, B. From virtual community members to C2C e-commerce buyers: Trust in virtual communities and its effect on consumers’ purchase intention. Electronic Commerce Research and Applications, 9, 4 (2010), 346–360. 65. MacQueen, K.M.; McLellan, E.; Metzger, D.S.; Kegeles, S.; Strauss, R.P.; Scotti, R.; Blanchard, L.; and Trotter, R.T. What is community? An evidence-based definition for participatory public health. American Journal of Public Health, 91, 12 (2001), 1929–1938. 66. Markopoulos, P.M., and Clemons, E.K. Reducing buyers’ uncertainty about tasterelated product attributes. Journal of Management Information Systems, 30, 2 (Fall 2013), 269–299. 67. Marsh, H.W., and Hocevar, D. A new, more powerful approach to multitrait-multimethod analyses: Application of second-order confirmatory factor analysis. Journal of Applied Psychology, 73, 1 (1988), 107–117. 68. Maslow, A.H.; Frager, R.; and Fadiman, J. Motivation and Personality. New York: Harper & Row, 1970. 69. Meyer, J.P., and Herscovitch, L. Commitment in the workplace: Toward a general model. Human Resource Management Review, 11, 3 (2001), 299–326. 70. Moore, G.C., and Benbasat, I. Development of an instrument to measure the perceptions of adopting an information technology innovation. Information Systems Research, 2, 3 (1991), 192–222. 71. Morgeson, F.P., and Hofmann, D.A. The structure and function of collective constructs: Implications for multilevel research and theory development. Academy of Management Review, 24, 2 (1999), 249–265. 72. Nabi, R.L.; Prestin, A.; and So, J. Facebook friends with (health) benefits? Exploring social network site use and perceptions of social support, stress, and well-being. CyberPsychology, Behavior & Social Networking, 16, 10 (2013), 721–727. 73. Nahapiet, J., and Ghoshal, S. Social capital, intellectual capital, and the organizational advantage. Academy of Management Review, 23, 2 (1998), 242–266. 74. Nevo, D., and Chan, Y.E. A Delphi study of knowledge management systems: Scope and requirements. Information & Management, 44, 6 (2007), 583–597. 75. Nonnecke, B., and Preece, J. Why lurkers lurk. Paper presented at the Americas Conference on Information Systems, Boston, 2001. 76. Nonnecke, B.; Preece, J.; Andrews, D.; and Voutour, R. Online lurkers tell why. Proceedings of the Tenth Americas Conference on Information Systems, New York, August 2004. http://www.cis.uoguelph.ca/~nonnecke/research/OnlineLurkersTellWhy.pdf?q=lurkers. 77. Nosko, A.; Wood, E.; and Molema, S. All about me: Disclosure in online social networking profiles: The case of facebook. Computers in Human Behavior, 26, 3 (2010), 406–418. 78. Nov, O.; Ye, C.; and Kumar, N. A social capital perspective on meta-knowledge contribution and social computing. Decision Support Systems, 53, 1 (2011), 118–126. 79. Oestreicher-Singer, G.; and Zalmanson, L. Content or community? A digital business strategy for content providers in the social age. MIS Quarterly, 37, 2 (2013), 591–616. 80. Okoli, C., and Pawlowski, S.D. The Delphi method as a research tool: An example, design considerations and applications. Information & Management, 42, 1 (2004), 15–29. 81. Pagani, M., and Mirabello, A. The influence of personal and social-interactive engagement in social TV Web sites. International Journal of Electronic Commerce, 16, 2 (Winter 2011–12), 41–68. 82. Pagani, M.; Hofacker, C.F.; and Goldsmith, R.E. The influence of personality on active and passive use of social networking sites. Psychology & Marketing, 28, 5 (2011), 441–456. 83. Park, D.-H.; Lee, J.; and Han, I. The effect of on-line consumer reviews on consumer purchasing intention: The moderating role of involvement. International Journal of Electronic Commerce, 11, 4 (Summer 2007), 125–148. 84. Park, N.; Jin, B.; and Annie Jin, S.-A. Effects of self-disclosure on relational intimacy in Facebook. Computers in Human Behavior, 27, 5 (2011), 1974–1983. 85. Pavlou, P.A.; Liang, H.; and Xue, Y. Understanding and mitigating uncertainty in online exchange relationships: A principal-agent perspective. MIS Quarterly, 31, 1 (2007), 105–136. 252 CHEN, LU, CHAU, AND GUPTA 86. Petter, S.; Straub, D.; and Rai, A. Specifying formative constructs in information systems research. MIS Quarterly, 31, 4 (2007), 623–656. 87. Pettijohn, T.F.; LaPiene, K.E.; and Horting, A.L. Relationships between Facebook intensity, friendship contingent self-esteem, and personality in U.S. college students. Cyberpsychology, 6, 1 (2012), 1–7. 88. Porter, C.E.; Devaraj, S.; and Sun, D. A test of two models of value creation in virtual communities. Journal of Management Information Systems, 30, 1 (Summer 2013), 261–292. 89. Preece, J., and Shneiderman, B. The reader-to-leader framework: Motivating technology-mediated social participation. AIS Transactions on Human-Computer Interaction, 1, 1 (2009), 13–32. 90. Qiu, L.; Rui, H.; and Whinston, A.B. Effects of Social Networks on Prediction Markets: Examination in a Controlled Experiment. Journal of Management Information Systems, 30, 4 (Spring 2014), 235–268. 91. Randall, W.S.; Gravier, M.J.; and Prybutok, V.R. Connection, trust, and commitment: Dimensions of co-creation? Journal of Strategic Marketing, 19, 1 (2011), 3–24. 92. Rau, P.L.P.; Gao, Q.; and Ding, Y. Relationship between the level of intimacy and lurking in online social network services. Computers in Human Behavior, 24, 6 (2008), 2757– 2770. 93. Riedl, R.; Mohr, P.N.C.; Kenning, P.H.; Davis, F.D.; and Heekeren, H.R. Trusting humans and avatars: A brain imaging study based on evolution theory. Journal of Management Information Systems, 30, 4 (Spring 2014), 83–114. 94. Roberts, S.G.B.; and Dunbar, R.I.M. Communication in social networks: Effects of kinship, network size, and emotional closeness. Personal Relationships, 18, 3 (2011), 439– 452. 95. Rosenblueth, A.; Wiener, N.; and Bigelow, J. Behavior, purpose and teleology. Philosophy of Science, 8, 1 (1985), 18–24. 96. Schultz, N., and Beach, B. From lurkers to posters. Australian National Training Authority, 14, 1 (2004), 4–23. 97. Shao, G. Understanding the appeal of user-generated media: A uses and gratification perspective. Internet Research, 19, 1 (2009), 7–25. 98. Sledgianowski, D., and Kulviwat, S. Using social network sites: The effects of playfulness, critical mass and trust in a hedonic context. Journal of Computer Information Systems, 49, 4 (2009), 74–83. 99. Son, J.Y., and Kim, S.S. Internet users’ information privacy-protective responses: A taxonomy and a nomological model. MIS Quarterly, 32, 3 (2008), 503–529. 100. Stephen, A.T., and Toubia, O. Deriving value from social commerce networks. Journal of Marketing Research, 47, 2 (2010), 215–228. 101. Stewart, K.A., and Segars, A.H. An empirical examination of the concern for information privacy instrument. Information Systems Research, 13, 1 (2002), 36–49. 102. Stieglitz, S., and Dang-Xuan, L. Emotions and information diffusion in social mediasentiment of microblogs and sharing behavior. Journal of Management Information Systems, 29, 4 (Spring 2013), 217–248. 103. Thelwall, M.; Wilkinson, D.; and Uppal, S. Data mining emotion in social network communication: Gender differences in MySpace. Journal of the American Society for Information Science and Technology, 61, 1 (2010), 190–199. 104. Tiwana, A., and Bush, A.A. Continuance in expertise-sharing networks: A social perspective. IEEE Transactions on Engineering Management, 52, 1 (2005), 85–101. 105. Trusov, M.; Bodapati, A.V.; and Bucklin, R.E. Determining influential users in Internet social networks. Journal of Marketing Research, 47, 4 (2010), 643–658. 106. Vergeer, M., and Pelzer, B. Consequences of media and Internet use for offline and online network capital and well-being. A causal model approach. Journal of ComputerMediated Communication, 15, 1 (2009), 189–210. 107. von der Gracht, H.A. Consensus measurement in Delphi studies: Review and implications for future quality assurance. Technological Forecasting and Social Change, 79, 8 (2012), 1525–1536. USERS’ ACTIVE BEHAVIOR ON SNSS 253 108. Wang, C., and Zhang, P. The evolution of social commerce: The people, management, technology, and information dimensions. Communications of the Association for Information Systems, 31, 1 (2012), 105–127. 109. Wang, F., and Head, M. How can the Web help build customer relationships? An empirical study on e-tailing. Information & Management, 44, 2 (2007), 115–129. 110. Watson-Manheim, M.B., and Bélanger, F. Communication media repertoires: Dealing with the multiplicity of media choices. MIS Quarterly, 31, 2 (2007), 267–293. 111. Yen, H.J.R.; Hsu, S.H.-Y.; and Huang, C.-Y. Good soldiers on the Web: Understanding the drivers of participation in online communities of consumption. International Journal of Electronic Commerce, 15, 4 (Summer 2011), 89–120. 112. Zhang, X., and Zhu, F. Intrinsic motivation of open content contributors: The case of Wikipedia. Workshop on Information Systems and Economics, Evanston, IL, 2006. http:// digital.mit.edu/wise2006/papers/3A-1_wise2006.pdf. 113. Zhou, Z.; Fang, Y.; Vogel, D.R.; Jin, X.-L.; and Zhang, X. Attracted to or locked in? Predicting continuance intention in social virtual world services. Journal of Management Information Systems, 29, 1 (Summer 2012), 273–306. 114. Zwass, V. Co-creation: Toward a taxonomy and an integrated research perspective. International Journal of Electronic Commerce, 15, 1 (Fall 2010), 11–48.