This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. ICT and Temporal Fragmentation of Activities: An analytical framework and initial empirical findings Christa Hubers* Tim Schwanen Martin Dijst Utrecht University Faculty of Geosciences Department of Human Geography and Planning PO Box 80.115 3508 TC Utrecht The Netherlands * Corresponding author Phone: +31-30-2532407 Fax: +31-30-2532037 E-mail: C.Hubers@geo.uu.nl 1 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. ABSTRACT It is commonly believed that the widespread use of Information and Communication Technologies (ICTs) facilitate the fragmentation of daily activities across times and spaces. However, a clear conceptualization of what fragmentation is and how it can be measured empirically has been lacking. As a consequence, hardly any empirical evidence has been provided for these notions. The goal of this paper is twofold: (1) to propose a theoretical and methodological framework for identifying and measuring activity fragmentation; and (2) to assess temporal fragmentation empirically and consider its associations with ICT usage while controlling for sociodemographic variables, residential context, day of the week, activity pattern characteristics and some attitudinal variables. Activity fragmentation is defined as a process whereby a certain activity is divided into several smaller pieces, which are performed at different times and/or locations. The proposed theoretical and methodological framework covers three main dimensions of fragmentation: the number of fragments; the distribution of the sizes of fragments; and the temporal configuration of fragments. Based on travel diary data from The Netherlands the analytical results are insightful and promising. The framework is not only capable of detecting temporal activity fragmentation for various trip purposes, but there are also indications of a positive relation between ICT-usage and temporal fragmentation. Keywords: Activity fragmentation; Information and Communication Technologies; The Netherlands 2 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. 1. INTRODUCTION It is commonly believed that, due to developments in Information and Communication Technologies (ICTs), “professional and social relations can be established and maintained almost equally easily over any distance across the globe” (Couclelis, 1996, p. 388). As a consequence, activities seem to be getting less firmly linked to fixed spatial locations and times which might be manifested in the fragmentation of activities into tasks that are widely distributed over space and across time (Couclelis, 2000; Dijst, 2004). This so-called ‘activity fragmentation’ is foreseen to have considerable impacts on the daily life of individuals. The fragmentation of daily activities across times and spaces facilitates the blurring of the boundaries between previously separated life domains of work, care and leisure and may offer new opportunities as well as challenges to people juggling paid labor and care giving responsibilities. It is furthermore foreseen to have considerable impacts on transportation flows since the predicted increases in travel demand that may result from activity fragmentation may increase road congestion across time (especially during what are now considered non-peak hours) and space (new bottlenecks in addition to existing ones). The demand for certain facilities and services may also decrease, manifest itself at other times, or facilities may experience alterations in their functions. E-shopping, for example, may ultimately reduce brick-and-mortar stores to showrooms for products that are than purchased on the Internet. Likewise, telecommuting may reduce the relevance of the physical nearness to the employment location when searching for a new residence (Ory and Moktharian, 2006). However, there is almost no empirical support for the propositions about activity fragmentation. Therefore, it is not known to what extent such fragmentation is indeed occurring, how it takes place and what the role of ICT in this process is. This is among others due to the fact that activity fragmentation as a concept is intuitively sensible but difficult to grasp theoretically, methodologically and empirically. There is not only a lack of a clear framework for analysing and measuring fragmentation but also of appropriate data. A first attempt to measure fragmentation empirically has been made by Lenz and Nobis (2007). Although these authors find some evidence of the occurrence of activity 3 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. fragmentation, their research does not provide a detailed insight into the ways in which activities are fragmented. It furthermore remains unclear what the relative strength of the relation is between ICT and activity fragmentation. There are reasons to believe that the extent of activity fragmentation is also related to sociodemographic factors or the residential and temporal context (cf. Hanson, 1982; Yamamoto and Kitamura, 1999). We expect ICTs to function as facilitators of fragmentation because they create new choice sets for the performance of activities in space and time, rather than them being determinants of fragmentation. We hypothesize that characteristics of both the activity and the individual determine whether or not these new options will actually be chosen (cf. Mokhtarian et al. 2006). In order to address these issues we aim, firstly, to develop a theoretical and methodological framework for measuring fragmentation of activities. Our second aim is to apply this framework on travel diary data in order to assess the relevance of ICT-usage for temporal activity fragmentation. For the development of the theoretical and methodological framework, an interdisciplinary approach is employed. This framework will be presented in Sections 2 and 3. Sections 4-5 introduce the empirical analysis in which we describe the fragmentation for paid labor, shopping for daily and non-daily goods, and leisure activities, and assess whether fragmentation varies systematically with ICT usage, and possible other factors that as we will argue below might have an influence on the level of fragmentation. Note that the exploratory analysis in the current paper will be confined to the fragmentation of activities across time. Although activity fragmentation is usually discussed as a phenomenon in both space and time, the unravelling of temporal patterns is so complex that a separate paper is warranted. The paper ends with conclusions and a discussion. 4 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. 2. AN INTERDISCIPLINARY APPROACH TO FRAGMENTATION 2.1. Defining Fragmentation To avoid re-inventing the wheel, we have conducted an interdisciplinary literature search about the nature of fragmentation and measurement approaches. Fragmentation is a notion used in social and natural sciences and applied on various divisible phenomena or objects. Sociologists have extensively studied the temporal fragmentation of (leisure) activities, often in relation to time pressure (e.g, Mattingly and Bianchi, 2003; Sullivan, 1997). In human geography, economic geography and spatial planning spatial fragmentation refers often to the development of socio-spatial specialised zones in relation with segmentation of infrastructures (Graham and Marvin, 2001), segmentation and relocation of economic activities (Arndt and Kierzowski, 2001) or decentralised landuse governance (Ulfarsson and Carruthers, 2006). Computer scientists Mark et al. (2005) have investigated the extent of fragmentation of work activities to find out whether the development of computer software programs assisting workers in picking up their work after interruptions is warranted. But probably the most well known application of the fragmentation concept in the world of computers is concerned with hard disk fragmentation (Diskeeper Corporation Europe, 2006). This fragmentation process implies that accessing fragmented computer files consumes more time and necessitates users to de-fragment their hard disks. Ecology is nonetheless the discipline contributing the most relevant insights for our study: a vast literature exists on forest and ecosystem fragmentation, on different dimensions of fragmentation, and on measurement approaches (Rutledge, 2003). While fragmentation has been studied in many research areas, each discipline employs its own specific definition to the concept. As a consequence, there is no unequivocal definition of fragmentation. Inspired by Couclelis (2003, page 11), we define fragmentation as: a process whereby a certain activity is divided into several smaller pieces, which are performed at different times and/or locations 5 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. Generally speaking, two types of activity fragmentation can be discerned: temporal fragmentation – different times at which the smaller sub-tasks are performed – and spatial fragmentation – different locations at which the sub-tasks are performed. The current paper focuses on the temporal fragmentation. An example helps to clarify the above definitions. Suppose a person wants to purchase a Flatscreen TV. She could start browsing the Internet for some general information on the types of Flat TVs available. She may then go to a brick-and-mortar electronics store to get a better grasp of the difference between Plasma and LCD technology and see with her own eyes the differences in the picture quality, and see which features she likes best. She may also read some independent product reviews on the Web or talk to Flat TV-owning friends, relatives or colleagues about their experiences. After having decided what TV to buy, she has to decide where to purchase it. Comparison sites on the Internet might be used to get the best bargain. Having chosen the dealer and consequently purchased the new Flat TV online, she finally has to determine how to have the product delivered, where and when. Not all purchases will be made in this or similar ways. But the example shows clearly that the activity of shopping for a certain product comprises several sub-tasks (e.g. searching and evaluating product information; purchasing the product; and transporting the product or having it delivered) and this probably holds for the majority of shopping activities (see also Salomon and Koppelman, 1988). These sub-tasks can exist of smaller fragments. We use the term ‘activity episode’ to denote the different times at which these smaller fragments a sub-task consists of are performed. If on a given day the individual in the above example in the morning talks to some colleagues at the office about their Flat TVs, stops by an electronics store to view some possible TVs after work and later at night browses the Internet for some more product information from home, the sub-task of searching and evaluating product information consists of three activity episodes throughout that single day. The term ‘activity location’ represents the different locations at which the smaller fragments of the sub-task are performed. Again taking the sub-task of searching and evaluating product information as an example, we may say this sub-task 6 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. is spatially fragmented across three activity locations: the employment location, the electronics store and the home. The example also indicates the significance of ICTs in this process. Due to ICTs, the number of times when and locations where activity episodes can be performed has increased dramatically now that they are no longer exclusively dependent on shop opening hours and locations. The discussion so far has not touched upon two complicating factors. First, our example does not make clear when an activity is fragmented as opposed to being two separate activities. In our view, the answer to this question greatly depends on the objectives of the study. If, for example, it seeks to examine whether the paid work activity of people who work from home is more often alternated with maintenance activities (activities that are performed for the upkeep of the household, such as cooking, cleaning and shopping) than is the case for people working in an office, a more general classification of paid and maintenance activities suffices. However, if one wants to find out whether the process of shopping for shoes is more or less fragmented than the process of shopping for a Flat TV, more detailed information on the sub-tasks that constitute both shopping activities is necessary. Second, there are several concepts, such as balkanization and contamination or multitasking, that are intimately associated with fragmentation. We will discuss these related concepts briefly to demarcate what topics will not be investigated but may still be relevant to (future studies of) activity fragmentation. The term balkanization refers to the division of a place or country into several small political units that are often unfriendly to one another (New Dictionary of Cultural Literacy, 2002). With respect to daily activities, balkanization is concerned with the ways people evaluate activity fragmentation. Mark et al. (2005) showed that an interruption of a certain work activity was evaluated more negatively when the interrupting task had nothing to do with the original task. The interruption was, however, evaluated less negatively and sometimes even considered beneficial, when the interrupting and disrupted tasks were associated with one another. It also mattered whether the interruption was self-induced or imposed externally with the former being less negatively evaluated than the latter. Contamination, or multitasking, is 7 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. derived from the sociological literature and is concerned with the fact that several activities can be performed simultaneously (Mattingly and Bianchi, 2003; Sullivan, 1997; Felker Kaufman et al., 1991). For instance, watching the television while eating, working on the train while travelling, or calling a friend with your cellular phone while standing in line at the grocery store. With multitasking the emphasis is on how at a single moment in time multiple activities are performed, whereas with temporal activity fragmentation the emphasis is on how a single activity is performed at multiple times and locations. Several transportation studies have indicated that Internet and mobile phone use stimulate multitasking (Kenyon and Lyons, 2007; Schwanen and Kwan, 2008). Since the description of temporal fragmentation is already very complex without addressing issues of how people experience it and the performance of multiple activities simultaneously, the latter two issues are left to future studies. 2.2 Dimensioning fragmentation According to the ecological literature in particular, fragmentation can be seen as composed of three dimensions (Figure 1). The most commonly identified dimension is the number of fragments or segments in which a given object (activity, forest or hard disk) is divided (Mattingly and Bianchi, 2003; Sullivan, 1997; Rutledge, 2003). Rutledge (2003, page 7) gives a simple but telling example: “A plate that is broken into 100 pieces is more fragmented than a plate broken into 10 pieces.” In our framework this means that when a certain sub-task is performed, for example, four times a day, this activity type counts four fragments, also called activity episodes. The second dimension concerns the distribution of sizes of the fragments. As Rutledge (2003, page 7) continues: “Similarly, a plate broken into 10 pieces of equal size is more fragmented than a plate broken into 10 pieces, one of which is 90% of the original plate.” This is also recognized in social science for employment-related (Mark et al., 2005) and leisure activities (Sullivan, 1997). Finally, the configuration of fragments is considered an important dimension of fragmentation in ecology (Rutledge, 2003). While Rutledge acknowledges that, in a strict 8 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. sense, configuration is not related to spatial fragmentation, he argues that the survival of plant and animal species depends on the configuration of their habitat fragments. If habitats become too isolated, the survival of plants and animals is threatened. Although it is probably not a matter of life and death in social sciences, studying the configuration of activity fragments can provide valuable insights into their timing. ICT use may imply that activity episodes become more spread out across the day. This is shown clearly in the example in Section 2.1 where the person gathers product information from her colleagues in the morning during office hours, after work just before the closing time of the electronics store and again later at night on the Internet which conveniently has no closing time. Fragmentation can have a direct or indirect effect on the timing of activity episodes. As ICTs reduce the space-time fixity of activities they have a direct effect on the timing of activity episodes (Schwanen and Kwan, 2008). ICTs however may also increase the efficiency with which activities are performed, thereby reducing their duration. And since short activity episodes are more readily slotted into individuals’ activity schedules than longer ones, ICTs may have an indirect effect on the timing of activity episodes. Information on the number and/or duration of activities is insufficient for determining whether they are rescheduled to alternative moments. The distribution of the sizes of the activity episodes only tells us something about the duration of these activity episodes. By taking into account the temporal distances between the different activity episodes, which are calculated in the configuration dimension, the exact timing of these activity episodes can also be determined. In short, we believe that the three dimensions should be analysed simultaneously even though they capture different aspects of activity fragmentation. The first two dimensions describe how much a certain activity is fragmented, whereas the third explains in what way the activity is fragmented and provides valuable insights into the spatial and temporal patterns that are formed by the different activity episodes and locations. 9 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. 2.3 Factors Associated with Fragmentation Based on previous research on determinants of activity and travel behaviour we expect that besides ICTs, other factors including sociodemographic factors, characteristics of the built environment (Hanson, 1982; Lu and Pas, 1999), factors concerning the day of the week (Yamamoto and Kitamura, 1999) and attitudinal variables (Farag et al., 2007) might also be related to the fragmentation of activities. Like Mokhtarian et al. (2006) we expect ICTs primary impact on activities is “to expand an individual’s choice set” (page 263), whereas characteristics of both the activity and the individual determine whether or not these new options will actually be chosen. Because the adoption of ICT and their use depends among others on socio-demographic factors, the effects of these variables should be controlled in an analysis of the associations between ICT ownership and use and activity fragmentation. This section provides a brief summary of the potential relations between other determinants of activity and travel behaviour and fragmentation. Previous studies have discussed the impact of ICT on activity fragmentation in general terms (Couclelis, 1996; Lenz and Nobis, 2007). However, ICT is a highly differentiated category of information and communication devices and services, ranging from PCs to cell phones and from voice call to email. Therefore, it can be hypothesized that fragmentation will probably increase with the number and variety of ICT devices owned and services used, and the purpose of use. The daily activity pattern of a person who owns multiple ICT devices (laptop, desktop computer and mobile phone, for instance) and uses them throughout the day and for different goals (communication, e-shopping, work) is more likely to be fragmented by ICTs than the activity pattern of a person who, say, only owns a desktop computer, is not very accustomed to using it, and only uses it to send e-mails. Sociodemographic characteristics can also affect activity fragmentation, both directly and indirectly (Hanson, 1982; Lu and Pas, 1999). The relatively strong level of space-time fixity of caring tasks (for instance, the chauffeuring of children), which are still largely a female responsibility (Dijst, 1999; Kwan, 1999; Schwanen et al., 2007), make us hypothesize that women’s activities will be more fragmented than those of men. Activity fragmentation could be seen as a strategy for women to reconcile the different 10 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. claims on their time-space resources (Kwan, 1999). And since the caring task load is higher if adults have small children, we expect persons with young children to have more fragmented daily activity patterns than persons without young children. Other sociodemographic variables that have been related to activity and travel behaviour and therefore may also be associated with the fragmentation of daily activity patterns are age and education (Hanson, 1982; Lu and Pas, 1999). Residential context, such as the number and accessibility of shops and other facilities, define the opportunities and constraints for the fragmentation of activities (Dijst et al., 2002; Ritsema van Eck et al., 2005). Since these opportunities are substantially larger in urban than in suburban areas, we expect people living in urban areas to have more fragmented activity patterns than their counterparts in suburban areas (Schwanen, 2004). Furthermore, since travelling by car increases the accessibility of facilities, commute mode is also expected to be related to activity fragmentation. A temporal factor expected to be related to the fragmentation of activities, is the difference between week- and weekend days (Yamamoto and Kitamura, 1999). On weekdays, paid labor, activities related to personal care and the caring for children at home, as well as chauffeuring young children to their schools, impose major time constraints on activity-travel patterns (Cullen and Godson, 1975; Kwan, 2000a; Doherty, 2006; Schwanen and Kwan, 2008). Hence, it can be expected that activities on weekend days are less fragmented than on other days. Finally, where the fragmentation of the shopping activity is concerned, earlier findings by Farag et al. (2007) indicate that people with positive attitudes towards shopping are willing to put more efforts into shopping. This may result in more shopping related activity episodes that require more or longer trips. On the other hand, the experience of time pressure can induce people to bundle their shopping activities resulting in less fragmentation. 11 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. 3. FRAGMENTATION INDICES Based on the dimensions of fragmentation discussed in Section 2.1, we now introduce the indicators developed for each dimension. Most of the indicators are based on the literature in ecology and sociology (e.g. Sullivan, 1997; Mattingly and Bianchi, 2003; Rutledge, 2003) and have been adjusted to the specific measurement of temporal fragmentation. The term ‘activity episode’ is used as a synonym for ‘activity fragment’. Details on the exact definitions of the indicators are available in Table 1. The temporal distances between the fragments characterise the distribution or configuration of these fragments in a certain time span. An important benefit of the three dimensions discerned in Section 2.2, is that they are applicable on multiple temporal scales. Whereas in the current research paper they are applied to investigate the temporal fragmentation of daily activity patterns, they can also be employed to study the fragmentation of weekly, monthly or even yearly activity patterns. 3.1 Number of Activity Episodes (NAE) This dimension makes a first and simple distinction between more or less fragmented activities by counting the number of different episodes of a certain activity in a day. Its interpretation is straightforward: the greater the number, the greater the fragmentation. 3.2 Distribution of Sizes The distribution of the sizes of the episodes is measured via three indicators: 1. The mean size of the different episodes an activity is divided into (MES); 2. The standard deviation of the episode sizes (SD ES), and; 3. The size of the largest episode (LEI). Since the mean is sensitive to outliers and very different episode combinations can have an identical mean episode size, we will also look at the size of the largest episode and the standard deviation of the episode sizes. A small standard deviation and small size of the largest episode indicate that the episodes are more equal in size and therefore more 12 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. fragmented. It is expected that the mean size of the episodes and the size of the largest episode are inversely related to the number of episodes. This would be in accordance with the work of Kitamura et al. (1981) who found that the number of episodes in a daily activity pattern and the duration per episode are negatively correlated. 3.3 Configuration The configuration indicators measure whether a certain activity is more or less spread across time and in what way. Their value primarily lies in their ability to describe in what way a certain activity is fragmented. This exercise, however, is only fruitful when the indicators allow for a distinction between global and local clustering as well as outliers. Global clustering refers to the degree to which episodes are located near or far from one another at the level of the total pattern of all activity episodes collectively. The term local clusters is used to indicate the occurrence of several smaller subgroups of fragments within the total temporal pattern, located at a certain temporal distance from one another. Furthermore, outliers are defined as single fragments that are separated relatively far in time from the other fragments. It does not suffice to consider only the average temporal distance between all fragments. This would only reveal the amount of global clustering of an activity and might cancel out the differences in temporal distance between pairs of fragments. In this case configurations B and C portrayed in Figure 1 would have a roughly similar average temporal distance between the episodes, even though their configurations are clearly different. It is therefore also relevant to study the possible occurrence of local clusters or outliers as shown in pictures D and E. Four indicators have therefore been developed: 1. The mean temporal distance between the episodes (MTD); 2. The standard deviation of the temporal distance between the episodes (SD TD); 3. The mean temporal distance from one episode to its nearest neighbouring episode (MNTD); and 4. The standard deviation of the temporal distance to the nearest neighbouring episode (SD NTD). 13 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. The mean temporal distance between the episodes (MTD) measures the time intervals between each episode and all other episodes. If there are more than two episodes, say three, the temporal distance between the first and third episode is calculated by subtracting the starting time of the third from the ending time of the first episode and discounting the duration of the second episode in-between. The use of the four indicators discerned here enables us to detect various different kinds of configurations. Table 2 offers an overview of how fragmentation patterns can be represented by the different combinations of mean temporal distance between the episodes (MTD) and its nearest neighbouring episode (MNTD) and their standard deviations. 4. RESEARCH DESIGN 4.1. Data Description The data used for the empirical analysis were originally gathered to examine the relationships between e-shopping and in-store shopping (Farag et al., 2007). It consists of a shopping questionnaire and a two-day travel diary and was collected NovemberDecember 2003. As the research was targeted toward shopping activities, the diaries were completed on a Friday and Saturday – the days of the week that most shopping is done in The Netherlands. It is important to notice that non-Internet users were excluded from the study, rendering it impossible to compare Internet users and non-Internet users in our study. Due to the thorough measurement of the frequency of Internet use, we are nonetheless capable of comparing frequent with infrequent Internet users. The research area consisted of four municipalities located in the heart of the Netherlands: Utrecht (270 243 inhabitants and a high level of shop availability); Nieuwegein (61 806 inhabitants, low level of shop availability and located 7 kilometres from Utrecht); Culemborg (26 613 inhabitants, high level of shop availability and located 17 kilometres from Utrecht); and Lopik (13 869 inhabitants, low level of shop availability and located 18 kilometres from Utrecht). 826 Respondents completed both a shopping questionnaire and a travel diary, of whom 44 percent participated online, and the rest used paper-and-pencil surveys. There 14 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. appears to be some selection bias in that highly educated persons, females and older persons are over-represented. Further information about the data collection process is available in Farag (2007). We have selected this data set because it allows us to assess the fragmentation of activities within daily activity patterns and its association with ICT use and other relevant factors. But since it was not originally designed to measure the fragmentation of activities, the data also has some important limitations. The main limitation lies in the fact that the travel diaries only contain information on the main activity that is undertaken at a certain location and not on the possible other types of activities that have been carried out at that destination. Furthermore, the categorization of activities is not sophisticated enough to allow us to discern possible sub-tasks, like searching for product information and purchasing of the product for the activity of shopping. However, the unique and comprehensive set of independent variables available in the data was an important advantage. Not only does it include a range of ICT indicators, but also information on respondents’ attitudes towards shopping and several characteristics of respondents’ residential context. The total number of respondents (826) also constitutes an advantage. Daily activity patterns tend to be very heterogeneous and data for many days or individuals is required if one wants to concentrate on specific activity types (paid labor, grocery shopping, etc.) of activities as we will do below. 4.2. Operationalisation of Variables and Analysis Activity episodes were determined as follows. In the travel diaries respondents could report a maximum of 15 trips per day. For each trip made they reported the destination type (school, work, home, supermarket, etc.) and street address information of this destination, as well as the exact departure and arrival time. The time spent at a certain destination type was considered an activity episode, so an episode is a sojourn at a single spatial location. If a trip to a certain destination type was followed by a trip to an identical destination type (for instance going to the baker’s shop followed by a trip to the butcher’s shop, both daily shopping activities) these were defined as two separate activity episodes (Burnett and Hanson, 1982; Harvey, 2003). 15 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. While comparing the temporal fragmentation of, for example, shopping for two specific product types (e.g. clothing compared to electronics) is certainly interesting, we concentrate on the differences in temporal fragmentation between more general activity categories in the current paper. It is expected that also on this broader level interesting differences between activity types are manifest. Therefore for our analysis four activity types were selected: paid labor: only includes visits to workplaces. daily shopping: market (10%1), supermarket (58%), a combined category (bakery, the greengrocery, the butcher’s store and the fish store (21%), and other (11%). non-daily shopping: clothing/footwear (13%), books/music (15%), department stores (13%), domestic appliances (10%), drug stores (9%), electronics (6%) and other (34%) leisure: social visits (50%), restaurant/café (23%), sports and hobbies (17%), theatre/cinema/museum (5%), other (6%). The factors potentially associated with fragmentation (Section 2.2) were derived from the shopping questionnaire. In total 18 variables have been defined and tested, which belong to the following categories: socio-demographics (8 variables); ICT factors (4); residential context (2); day of the week (1); and activity pattern characteristics (3). Some behavioral and attitudinal characteristics were also available from the shopping questionnaire. Principal factor analysis was applied to derive certain attitudes from a list of statements of which respondents were asked whether they agreed or disagreed. Agreement could be stated on a scale of 1 (totally disagree) to 7 (totally agree). Both for shopping behavior as for personality, only the third component was part of the final regression models presented in Section 5. With regard to shopping behavior this component seems to represent the efficiency of daily shopping. The personality component seems to reflect having a risk-averse personality. Unfortunately the shopping questionnaire did not contain any information on people’s evaluation of activity fragmentation, so the relation this might have with the amount of activity fragmentation cannot be assessed at this time. 1 Percentage represents part of the total general activity that was spent at this specific destination type. 16 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. To determine the extent of fragmentation of the four different activity types, the mean scores on the eight different fragmentation indicators were computed for all four activities separately. Regression analysis was used to analyze the relative strength of the associations between the eight fragmentation indicators and the independent variables mentioned above. In the regression models discussed in Section 5 only variables that were statistically significant at p < 0.1 were included in the final model specifications. 5. RESULTS 5.1. Descriptive analysis Based on the mean indicator values for the dimensions of the number of activity episodes and the distribution of episode sizes (Table 3), non-daily shopping appears to be the most fragmented activity of the four activity types considered. Not only does the activity of non-daily shopping consist of more different activity episodes than do paid labor, daily shopping and leisure (NAE), but these episodes also last shorter (MES) and are more equal in size (SD ES & LEI) than those of most other activities. As expected, the number of episodes is lowest and the duration per episode longest for paid labor. The configuration of the activity episodes indicators provides information on the pattern formed by the activity episodes. According to the mean temporal distance between episodes (MTD) the time-spans between leisure episodes are the longest, namely two hours and twenty minutes on average. Somewhat surprising is the finding that the time-spans between daily shopping episodes are also quite long (one hour and 35 minutes), since it would appear to be more efficient to chain these different daily shopping episodes together. Perhaps the large MTD for daily shopping is a result of the long opening hours of supermarkets that allow one to do some groceries during the lunch break and the remaining groceries in the evening after work (see Figure 2). The large temporal distances may also reflect that needs for (certain) 17 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. daily products manifest themselves at different moments during the day. The relatively short MTD of 58 minutes for non-daily shopping reflects that non-daily shopping episodes are often chained together (see also Figures 2 and 3). It is noteworthy that the MTD and the mean temporal distance from one episode to the nearest neighbouring episode (MNTD) are quite similar for paid labor, daily shopping and leisure. This is because the majority of respondents participate in these activity types at most twice per day, in which case the MTD and the MNTD are identical to one another. When the activity on average consists of several episodes the combination of the MTD and MNTD can provide insight into whether and how these episodes are spread across time. For example, since the MNTD for non-daily shopping is lower than the MTD, there is reason to believe that some activity episodes have smaller temporal distances than others, thereby forming one or more local clusters. This claim is substantiated by the standard deviations of the temporal distances between the episodes (the SD TD and SD NTD). In order to be able to compare the configurations of the activity episodes of paid labor, daily- and non-daily shopping, and leisure we have corrected the standard deviations for differences in mean temporal distances between the episodes of the three activity types by calculating the coefficient of variation (cv, results not shown here). Since paid labor has the lowest cv scores, this in combination with the other results tells us that paid labor is globally rather clustered (between 9:00 AM and 6:00 PM). Compared to daily shopping and leisure which have more extended business hours, the MTD for paid labor is rather low (see also Figures 2 and 3). Non-daily shopping episodes are also globally more clustered than daily shopping and leisure episodes. Leisure and daily shopping have the largest time intervals between episodes, which in combination with the considerable variation in the temporal distance indicators seems to be indicative of the existence of local clusters in combination with an outlier (see Figure 1, configuration E). 18 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. 5.2. Multivariate Analysis Due to data limitations, it was only possible to perform regression analyses for five of the eight indicators. Furthermore, since the majority of the activities consist of at most one or two episodes, the analyses for the number of activity episodes (NAE) and largest episode index (LEI) yielded strongly similar results. For the sake of efficiency, only the results of the analysis of the NAE are presented along with those for the mean episode size (MES), the mean temporal distance between the episodes (MTD) and the mean temporal distance from one episode to its nearest neighbouring episode (MNTD). Tables 4 and 5 present the significant unstandardized regression coefficients (B) and the standardized regression coefficients (β) for the different models. The βs allow comparisons of the relations of the different independent variables with the dependent variable. The R2 statistic, which can range from 0 to 1, indicates the goodness-of-fit of the model. It should be noted, however, that the R2 is influenced by the number of cases (N) in the model, in that fewer cases usually result in a larger R2. As will be seen, the R2 of the models on average is not very high, which might indicate the absence of important variables in the model or a small amount of variance in the fragmentation indicators. When the variance in the dependent variable is rather small, the independent variables have to be much more sensitive to the finer nuances in the dependent variable. This usually results in fewer statistically significant relationships between dependent and independent variables in a regression model. Paid Labor. ICT usage is positively related to the fragmentation of paid labor. Frequent Internet users appear to have more work episodes than infrequent Internet users. However, the duration of these work episodes (MES), and the time-spans between them (MTD and MNTD) do not differ between frequent and infrequent Internet users. This is in line with the work of Couclelis (2004) and Lenz and Nobis (2007). The number of hours of paid labor is the only sociodemographic variable that is related to the fragmentation of paid labor. People with more hours of paid labor not only have more work episodes (NAE), but these episodes also have longer durations (MES). There is also a relation between the residential context and the number of work episodes in that people 19 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. living in the suburb of Nieuwegein have more work episodes than people living in the other three municipalities The variables with the largest βs, and therefore with the strongest relations with all fragmentation indicators for paid labor, are the activity pattern characteristics, in particular the bringing away or picking up of something or somebody (chauffeuring). It seems that chauffeuring tasks form an indicator of a generally high amount of care giving responsibilities among some respondents, like bringing and picking up their children from schools or day care centers and daily shopping at certain fixed moments in time. The juggling of these care giving responsibilities with other tasks results in the fragmentation of work-related tasks (see also Hanson and Pratt, 1995; Kwan 1999; Schwanen, 2007). Other activity pattern characteristics related to the duration of work episodes (MES) are the number of days one works from home, and whether the workday is a Saturday. For people working from home, and those working on a Saturday work episodes are shorter, all as could be expected. Daily Shopping. The results for daily shopping show a rather different picture. With regard to ICT factors, the models show that persons whose primary use of the Internet does not take place in the home or at work, show more fragmented daily shopping patterns. They have a larger number of daily shopping episodes (NAE) and these shopping episodes on average last shorter (MES) than those of persons who primarily use the Internet at home or at the office. This is probably due to the fact that the group of respondents who most often use the Internet at other locations than in the home or at work largely consists of students and mobile professionals who are known to have more fragmented daily shopping patterns (Kakihara and Sorenson, 2002). In this case the primary location at which Internet is used is more likely to function as a proxy for occupation type than having an autonomous effect on the fragmentation of the daily shopping activity. It therefore does not contribute any knowledge regarding the question whether ICTs are positively associated with activity fragmentation. Further, persons who search for product information on the Internet, but buy the product in-store, have fewer but at the same time longer daily shopping episodes. At first glance, this result is not as 20 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. expected since it seems to indicate that ICT usage is related to less instead of more fragmentation (less and longer episodes instead of more and shorter episodes). It appears that the persons who search online and buy in-store bundle or defragment these shopping episodes, resulting in fewer but longer shopping episodes. This is further substantiated by the fact that people who prefer to shop efficiently, and those who have a risk-averse personality (a factor that among others consists of the statement that one likes to combine shopping with other activities), also have longer shopping durations. The number of ICT devices a person owns is positively related to the temporal distances between daily shopping episodes (MTD and MNTD) which are about 27 minutes longer for owners of multiple ICT devices. The daily shopping patterns of owners of multiple ICT devices are temporally less clustered and thus differ from those of persons who own few or none ICT devices. These results thus seem to indicate that ICTs are more likely to be associated with the defragmenting of daily shopping activities, as well as to temporally less clustered daily shopping patterns. Several of the sociodemographic variables are related to the fragmentation of daily shopping. Age, for instance, has the strongest relation with the number of daily shopping episodes (NAE) in that older people tend to have more of them. Their daily shopping episodes are also more clustered than those of younger people, as shown by the shorter time-spans between the shopping episodes, represented by the mean temporal distance between the episodes (MTD), and the mean temporal distance from one episode to its nearest neighbouring episode (MNTD). This seems to reflect that older people have larger time windows (time-blocks in which one is free to engage in out-of-home nonwork activities and travel, Forer and Kivell, 1981) at their disposal for daily shopping, whereas younger people have several smaller time windows available for daily shopping, forcing the latter to split up and divide the daily shopping activity across the day (Srinivasan and Bhat, 2005). The number of daily shopping episodes is also larger for women and highly educated persons and for the latter these episodes are also more clustered than for their counterparts. As is well known, women tend to perform more daily shopping episodes 21 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. than men because they still take on the most responsibility for social reproductive activities like daily shopping (Kwan, 1999; Schwanen et al., 2007). As for the differences between the educational levels, this might reflect a different taste in daily shopping goods, resulting in visits to various specialist shops by highly educated respondents, instead of a single supermarket. Persons experiencing a mobility constraint in the form of a handicap or illness on average have 18 minutes longer daily shopping episodes compared to people without such a constraint because the handicap slows them down. Furthermore, of all the variables tested in the models, the commuting mode has the strongest relation with the mean temporal distance between the episodes (MTD) and its nearest neighbouring episode (MNTD) for daily shopping. The temporal intervals between the shopping episodes of car commuters are much shorter than those of persons who go to work on foot, bicycle or public transport. People who commute by car work further away from their place of residence, resulting in a larger commute time, which leaves less time to do the shopping. Although people who commute by public transport are also likely to have long commute times, a car is more flexible and therefore better suited to visit different shopping locations than public transportation is. Residential context has the strongest relation with the mean shopping episode duration (MES) for daily shopping. A shopping duration in Lopik on average lasts 13 minutes longer than in the other municipalities. This probably reflects the fact that the duration of an activity is related to the travel time associated with that activity (Dijst and Vidakovic, 2000). Longer trips are usually only undertaken for activities with a longer duration. Since Lopik has a low level of shop availability, its residents might be inclined to employ a bundling strategy to save on shopping related travel time and make the activity duration worth the long trip. One activity pattern characteristic and the day of the week are also related to the fragmentation of daily shopping. On workdays the number of shopping episodes as well as the average duration of these shopping episodes is smaller, reflecting that paid labor 22 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. leaves less time for shopping. Furthermore, on Saturdays daily shopping episodes are more clustered which might reflect a bundling strategy of people who have little time to do the shopping on weekdays because of work obligations. Non-Daily Shopping. Perhaps the most telling about the results for non-daily shopping (Table 5), is the fact that there are only a small number of statistically significant results. This gets even more puzzling when we take into account the fact that of all four activities, non-daily shopping was the most fragmented one, as was shown in Section 5.1. The low model fit is probably due both to the absence of other important variables, and the small amount of variance in the fragmentation indicators. The ownership of ICT devices is the only ICT variable that is related to the fragmentation of non-daily shopping. As hypothesized, the more devices a person owns, the more non-daily shopping episodes he or she has. There is also a weak relation between the number of days a person works from home, an activity pattern characteristic, and the mean temporal distance between episodes. The more days one works from home, the stronger the clustering of non-daily shopping episodes. Educational attainment is the only sociodemographic variable related to the fragmentation of non-daily shopping. Being highly educated implies shorter and more clustered non-daily shopping episodes. This might be because highly educated persons tend to engage more in comparison shopping (Hanson, 1982). Residing in Culemborg is one of the two residential context variables related to non-daily shopping. People from Culemborg have more non-daily shopping episodes than people living in the other three municipalities. This might reflect the town planning of Culemborg which offers a somewhat unusual mix of stores for both daily and non-daily shopping2. Further analysis has shown that this is conducive to the chaining of daily and non-daily shopping episodes in Culemborg. In more urbanized areas the non-daily shopping episodes have a longer duration, possibly because they offer more and larger stores for the consumer to dwell in. On the website of Culemborg, the city centre is typified as “a convenience-centre, where not only can the consumer shop for daily products, but also do some recreational shopping.” (Gemeente Culemborg, 2007). 2 23 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. Leisure. The location where one uses the Internet most often is the only ICT variable related to the fragmentation of leisure activities. People who primarily make use of the Internet at their workplace tend to have more leisure episodes. Perhaps this is because these people are mainly to be found in certain professions related to the creative class, that are associated with lifestyles that are more focused on out-of-home leisure activities. If this is the case, job characteristics have an indirect relation with the fragmentation of leisure activities through the primary location of Internet use. This result is therefore not necessarily in line with the expectations that were formulated in other activity fragmentation literature since the positive relation between ICTs and activity fragmentation may in fact be a proxy for job characteristics. Several sociodemographic variables are related to the fragmentation of out-of-home leisure. Older people tend to have fewer leisure episodes, but it cannot be said that their out-of-home leisure activities are less fragmented than those of younger people, since the time-spans between the episodes are larger for older people. This seems to reflect that older people have more free time at their disposal and are therefore capable to combine a leisure activity in the morning with one in the afternoon, whereas people who have to work during the day will most likely postpone leisure activities until after work. Men also have more leisure episodes than women. People with children under the age of twelve tend to have a more fragmented leisure pattern. Not only do their leisure episodes last 36 minutes shorter on average than those of people without children in this age class, the time-spans between the different leisure episodes also are much longer, indicating less clustering of episodes. This probably reflects the fact that people with small children have very little leisure time left after all paid and unpaid labor is done (SCP, 2004). In addition, a lot of the leisure time of parents is spent with and also for their children, for instance when attending the soccer match of a child on Saturday morning. Whereas working people without young children at least have the evenings for themselves, the evenings of people with children are taken up with caring for their children. 24 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. Because of the considerable commute time of public transport commuters, which leaves less time for leisure activities, their leisure episodes have a shorter duration than people who use other commuting modes. Furthermore, the more cars available in the household, the larger the time-span between one leisure episode, and the directly preceding or following leisure episode (MNTD). When there are more cars in the household, household members might be more inclined to visit leisure activities that are located further away from each other, resulting in more travel time and larger temporal distances between episodes. Two of the activity pattern characteristics are related to the fragmentation of leisure. On a workday the number of leisure episodes is smaller. Having two or more chauffeuring duties is the most strongly related to the number of leisure episodes (NAE), and the average duration of these episodes (MES). The more chauffeuring tasks, the more leisure episodes, and the shorter the duration of these episodes. 6. CONCLUSIONS AND DISCUSSION Given that the literature on activity fragmentation has so far been mainly conceptual, this paper had a double goal: proposing a theoretical and methodological framework for analyzing activity fragmentation; and empirically assessing the extent of temporal fragmentation and its associations with ICT usage, while controlling for sociodemographic variables, residential context, day of the week, activity pattern characteristics and some attitudinal variables. A framework has been built around three dimensions of fragmentation: the number of fragments; the distribution of the sizes of fragments; and the temporal configuration of fragments. Applying the framework to existing travel-diary data has demonstrated its capability of distinguishing between more and less fragmented activities and differences in the configuration of these fragments. Our findings suggest that there is no straightforward relation between ICT-usage and temporal fragmentation, but rather a complex set of sometimes counter-acting relations. 25 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. The analysis has shown that for each of the four activity types considered ICTs are related to at least one fragmentation indicator, most often in a positive way. By and large, our analysis is consistent with the expectation in the literature (Couclelis, 2000; Dijst, 2004; Lenz and Nobis, 2007) that ICT ownership and use is associated with more activity fragmentation. More specifically, the number of work episodes for instance was positively related to the frequency of Internet usage. For daily shopping several ICT variables were related to the fragmentation of daily shopping episodes, though contrary to our expectations one of them, searching online to buy in-store, had a negative sign. The number of ICT devices one owns is positively related to the number of non-daily shopping episodes and the number of leisure episodes is related to the primary location of Internet use. So although the results show mostly positive relations between ICTs and fragmentation, these relations differ for the kind of ICT and kind of activity investigated. This, we believe, is an important notion which should be taken into account in the development of future research on activity fragmentation. Nonetheless, non-ICT variables were always related with fragmentation more strongly than ICT ownership and use in every model. Chauffeuring, for instance, had a strong impact on the fragmentation of paid labor and leisure activities, and in most models such sociodemographic variables as age, presence of children and educational level have more and stronger relations with fragmentation than ICTs have. Since we expect ICTs to create the necessary conditions for fragmentation to occur and thus function as facilitators rather than as determinants of fragmentation, these results are not surprising. In future studies, an analysis of temporal fragmentation of activities should preferably be based on activity diaries which allow us to consider the different activity types performed at a certain destination. The data should also enable the analysis of the series of sub-tasks and activity episodes that constitute a given activity. The general activity of shopping, for instance, should be unravelled into the sub-tasks of searching for product information and the purchasing of the product. Furthermore, such data should also allow studying the related concept of multitasking which was briefly discussed in Section 2.1. Information on primary and secondary activities that are performed simultaneously could help 26 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. substantiate the claim put forward in several transportation studies that Internet and mobile phone use stimulate multitasking. Otherwise, when a person for instance works while travelling home by train, and commuting is the primary activity, the secondary work activity would not be detected. Finally, to determine whether fragmentation results in highly flexible daily activity patterns, or whether these patterns remain rather fixed even though they are more fragmented, the time scale of the data could be expanded from the two days of the current paper to preferably several weeks (Kitamura et al., 2006). The framework proposed in this paper may also be extended in future research by considering the possible relations between the four different activity types that were analyzed in isolation from one another in the current study. Analysis of the total daily activity pattern they form may offer important insights into whether ICT ownership and use is, for example, associated with an increased alternation of paid labor with maintenance and/or leisure activities. It is also important to address the ways in which respondents experience and evaluate activity fragmentation and not limit oneself to the study of actual behaviour as was done in the current study (Adams, 1995, 2000, 2005; Kwan, 2000b). After all, the technical feasibility to be able to fragment activities does not guarantee that people will actually do so. If people evaluate fragmentation negatively, they are probably less prone to fragment their activities, and the futuristic views of highly fragmented daily activity patterns will never actualize. REFERENCES Adams, P., 1995, A reconsideration of personal boundaries in space-time, Annals of the Association of American Geographers, 85 (2), 267-285 Adams, P., 2000, Application of a CAD-based accessibility model. In: D.G. Janelle and D.C. Hodge (eds.), Information, Place and Cyberspace: Issues in accessibility. Berlin: Springer Verlag, 217-239 Adams, P., 2005, The boundless self: communication in physical and virtual spaces. New York: Syracuse University Press Arndt, S. and H. Kierzkowski, 2001, Fragmentation: New Production and Trade Patterns in the World Economy, Oxford: Oxford University Press Burnett, P. and S. Hanson, 1982, The analysis of travel as an example of complex human behavior in spatially-constrained situations: Definition and measurement issues, 27 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. Transportation Research A, 16 (2), 87-102 Couclelis, H., 1996, Editorial: the death of distance, Environment and Planning B, 23, 387-389 Couclelis, H., 2000, From sustainable transportation to sustainable accessibility: Can we avoid a new tragedy of the commons? In: D.G. Janelle and D.C. Hodge (eds.), Information, Place and Cyberspace: Issues in accessibility. Berlin: Springer Verlag, 341-356 Couclelis, H., 2003, Housing and the new geography of accessibility in the information age, Open House International, 28 (4), 7-13 Couclelis, H., 2004, Pizza over the internet: e-commerce, the fragmentation of activity and the tyranny of the region, Entrepreneurship and Regional Development, 16 (1), 41-54 Cullen, I., and V. Godson, 1975, Urban networks: the structure of activity patterns, Progress in Planning, 4 (1), 1-96 Dijst, M., (1999), Two-earner families and their action spaces: a case study of two Dutch communities, GeoJournal, 48 (3), 195-206. Dijst, M., 2004, ICT and accessibility: an action space perspective on the impact of new information and communication technologies. In: M. Beuthe, V. Himanen, A. Reggiani and L. Zamparini (eds.), Transport Developments and Innovations in an Evolving World. Berlin: Springer, 27-46 Dijst, M., Vidakovic, V., 2000. Travel time ratio: the key factor in spatial reach, Transportation, 27 (2), 179–199 Dijst, M., T. de Jong and J. Ritsema van Eck, 2002, Opportunities for transport mode change: an exploration of a disaggregated approach, Environment and Planning B: Planning and Design, 29 (3), 413-430 Diskeeper Corporation Europe. Available at: http://www.diskeepereurope.com/en/01_ho/xhtml/dk_home_overview.htm (Accessed July 12, 2006) Doherty, S.T., 2006, Should we abandon activity type analysis? Redefining activities by their salient attributes, Transportation, 33 (6), 517-536 Farag, S., T.Schwanen, M. Dijst and J. Faber, 2007, Shopping on-line and/or in-store? A structural equation model of the relationships between e-shopping and in-store shopping, Transportation Research A, 41 (2), 125-141 Felker Kaufman, C., P.M. Lane and J.D. Lindquist, 1991, Exploring more than 24 hours a day: a preliminary investigation of polychronic time use, The Journal of Consumer Research, 18 (3), 392-401 Forer, P.C. and H. Kivell, 1981, Space-time budgets, public transport, and spatial choice, Environment and Planning A, 13 (4), 497-509 Gemeente Culemborg, 2007, http://www.culemborg.nl/tDocumenten/detail.aspx?pKey1=201163808&pageid= 13420 (Accessed at January 23, 2007). Graham S., and S. Marvin, 2001, Splintering Urbanism: Networked Infrastructures, Technological Mobilities and the Urban Condition, London: Routledge. Hanson, S., 1982, The determinants of daily travel-activity patterns: relative location and sociodemographic factors, Urban Geography 3 (3), 179-202 Hanson, S., and G. Pratt, 1995, Gender, work and space, London: Routledge 28 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. Harvey, A. S., 2003, Time-space diaries: Merging traditions. In P. Stopher, and P. Jones (Eds), Transport Survey Quality and Innovation. Oxford: Elsevier, 152-180 Kakihara, M. en C. Sørensen, 2002, Mobility: an extended perspective, Proceedings of the 35th Hawaii International Conference on System Sciences (HICSS-35). IEEE, Big Island, Hawaii. 7th-10th January 2002 Kenyon, S. and G. Lyons, 2007, Introducing multitasking to the study of travel and ICT: Examining its extent and assessing its potential importance, Transportation Research A, 41 (2), 161-175 Kitamura, R., L.P. Kostyniuk and M.J. Uyeno, 1981, Basic properties of urban timespace paths: empirical tests, Transportation Research Record 794, 8-19 Kwan, M.-P., 1999, Gender, the home-work link, and space-time patterns of nonemployment activities, Economic Geography, 75 (4), 370-394 Kwan, M.-P., 2000a, Gender differences in space-time constraints, Area, 32 (2), 145-156 Kwan, M.-P., 2000b, Human extensibility and individual hybrid-accessibility in spacetime: a multi-scale representation using GIS. In: D.G. Janelle and D.C. Hodge (eds.), Information, Place and Cyberspace: Issues in accessibility. Berlin: Springer Verlag, 241-256 Lenz, B and C. Nobis, 2007, The changing allocation of activities in space and time by the use of ICT – “Fragmentation” as a new concept and empirical results, Transportation Research A, 41 (2), 190-204 Lu, X. and E. I. Pas, 1999, Socio-demographics, activity participation and travel behaviour, Transportation Research A, 33 (1), 1-18 Mark, G., V.M. Gonzalez and J. Harris, 2005, No task left behind? Examining the nature of fragmented work. Available at: http://portal.acm.org/citation.cfm?id=1054972.1055017 (Accessed July 12, 2006) Mattingly, M.J. and S.M. Bianchi, 2003, Gender differences in the quantity and quality of free time: the U.S. experience, Social Forces, 81 (3), 999-1030 Mokhtarian, P., I. Salomon and S.L. Handy, 2006, The impacts of ict on leisure activities and travel: a conceptual exploration, Transportation, 33 (3), 263-289 New Dictionary of Cultural Literacy, The, Third edition, 2002. Available at: http://www.bartleby.com/59/13/balkanizatio.html (Accessed July 12, 2006) Ory, D. and P. Mokhtarian, 2006, Which came first, the telecommuting or the residential relocation? An empirical analysis of causality, Urban Geography, 27 (7), 590-609 Ritsema van Eck, J., G. Burghouwt and M. Dijst, 2005, Lifestyles, spatial configurations and quality of life, Journal of Transport Geography, 13 (2), 123-134 Rutledge, D., 2003, Landscape indices as measures of the effects of fragmentation: can pattern reflect process? New Zealand Department of Conservation Salomon, I. and F. Koppelman, 1988, A framework for studying teleshopping versus store shopping, Transportation Research A, 22 (4), 247-255 Schwanen, T., 2004, The determinants of shopping duration on workdays in the Netherlands, Journal of Transport Geography, 12 (1), 35–48 Schwanen, T., 2007, Gender differences in chauffeuring children among dual-earner families, The Professional Geographer, 59 (4), 447-462 Schwanen, T., D. Ettema and H. Timmermans, 2007, If you pick up the children, I’ll do the groceries: spatial differences in between-partner interactions in out-of-home household activities, Environment and Planning A, 39 (11), 2754-2773 29 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. Schwanen, T. and M.-P. Kwan, 2008, The Internet, mobile phone and space-time constraints. Geoforum, forthcoming SCP, 2004, Trends in Time. The Use and Organisation of Time in the Netherlands. The Hague: Social and Culture Planning Office of the Netherlands. Srinivasan, S., and C. R. Bhat, 2005, Modeling household interactions in daily in-home and out-of-home maintenance activity participation, Transportation, 32 (5), 523544 Sullivan, O., 1997, Time waits for no (wo)man: an investigation of the gendered experience of domestic time, Sociology, 31 (2), 221-239 Ulfarson, G.F.. and J.I. Carruthers, 2006, The cycle of fragmentation and sprawl: a conceptual framework and empirical model, Environment and Planning B, 33 (5), 767-788 Yamamoto and Kitamura, 1999, An analysis of time allocation to in-home and out-ofhome discretionary activities across working days and non-working days, Transportation, 26 (2), 211-230 30 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. FIGURE 1 Three dimensions of fragmentation. 31 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. TABLE 1 Description of Configuration Measures Dimension Name Symbol Description Number Number of activity episodes NAE Counts the number of activity episodes Distribution Mean episode size MES Divides the total activity duration by the number of activity episodes. Results are always larger than 0 Episode size variation SD ES Calculates the standard deviation of the episode durations Largest episode index LEI Divides the episode with the longest duration by the total activity duration and multiplies it by 100 Mean temporal distance between MTD Divides the sum of all temporal distances between episodes by the number of temporal distances Configuration episodes Variation in temporal distance between episodes SD TD Calculates the standard deviation of the temporal distance between episodes MNTD Divides the sum of all temporal distances to nearest neighbouring episode by the number of temporal between episodes Mean temporal distance from one episode to its nearest neighbouring distances to its nearest neighbouring episode episode Variation in temporal distance to the SD NTD Calculates the standard deviation of the temporal distances to its nearest neighbouring episode nearest neighbouring episode 32 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. TABLE 2 Fragmentation Patterns and their Indicator Values Temporal fragmentation Pattern 0 0 0 0 0 Indicator values 24 24 24 24 24 MTD SD TD MNTD SD NTD low low low low MTD SD TD MNTD SD NTD high low high low MTD SD TD MNTD SD NTD high high low low MTD SD TD MNTD SD NTD low medium medium medium MTD SD TD MNTD SD NTD high high high high Description of fragmentation pattern A: Global clustering B: Spread out evenly C: Multiple local clusters D: Global cluster and outlier E: Multiple local clusters and an outlier 33 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. TABLE 3 Fragmentation of the Activity Types Paid Labor, Daily and Non-Daily Shopping, and Leisure Number of activity episodes Episode size Distribution Configuration of activity episodes Paid labor Mean N obs. 1.27 380 363.1 380 109.3 81 92.2% 380 50.6 81 33.3 19 45.7 81 SD NTD 19.0 19 Daily Shopping Mean N obs. 1.54 623 25.6 623 12.1 225 88.4% 623 94.4 225 67.1 67 81.1 225 50.6 67 Non-daily Shopping Mean N obs. 2.12 459 32.2 459 13.9 230 78.6% 459 58.3 230 50.1 125 37.2 230 29.5 125 Leisure Mean N obs. 1.62 561 140.5 561 81.4 227 86.7% 561 140.7 227 102.2 79 117.2 227 81.0 79 NAE MES SD ES LEI MTD SD TD MNTD 34 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. FIGURE 2 Timing of the four different activities on Friday 150 Frequency 125 100 Work Daily shopping Non-daily shopping Leisure 75 50 25 0 1 3 5 7 9 11 13 15 17 19 21 23 Starting time 35 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. FIGURE 3 Timing of the four different activities on Saturday 150 Frequency 125 100 Work Daily shopping Non-daily shopping Leisure 75 50 25 0 1 3 5 7 9 11 13 15 17 19 21 23 Starting time 36 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. TABLE 4 Regression Analyses for the Fragmentation of Work and Daily Shopping Activities Paid labor Number of episodes B Constant Mean episode size β 0.641*** B β 336.2*** Gender Handicap Frequency internet use Primary Internet use not at home or work Search online, buy in-store Efficiency daily shopping Risk-averse personality Number of days working from home Number of ICT devices owned Nieuwegein Lopik Saturday Workday Commute by car 0.089** 0.045** 0.11 6 24.6** B β 41.8*** Number of episodes B Mean episode size β 1.059*** B β 22.7*** 0.012*** 0.164 -0.149* -0.077 0.190** 0.103 Mean temporal distance between the episodes B β 209.4*** Mean temporal distance episode to its nearest neighbouring episode B β 211.1*** -1.6** 0.179 -1.8** 0.202 -43.1** 0.189 -51.4*** 0.230 27.0** 0.163 26.3** 0.163 -40.5** 0.177 -44.6** 0.199 -61.0*** 0.265 -.57.8*** 0.257 0.109 18.9*** 0.158 0.13 0 -13.2*** 0.161** Mean temporal distance between the episodes 46.3*** Age Male Number of hours paid labor High education Daily shopping Mean temporal distance episode to its nearest neighbouring episode B β 0.356* 0.072 -11.1* -0.075 -0.194** -0.099 8.4*** 0.145 3.2*** 0.122 3.6*** 0.131 -0.160 0.10 4 13.5*** -75.5*** 0.160 -0.164 -0.219** -0.104 -.6.9*** -0.110 37 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. Picking up/bringing away once Picking up/bringing away two or more times R2 N 0.322*** 0.20 0 0.087 380 -101.8*** -0.214 -87.0*** -0.165 0.131 380 34.6** 0.064 81 0.25 3 31.6** 0.065 81 0.255 0.073 623 0.119 623 0.172 225 0.194 225 *p < 0.1; ** p < 0.05; *** p < 0.01 38 This is a pre-publication version of the following article: Hubers, C., Schwanen, T. And Dijst, M. (2008). ICT and temporal fragmentation of activities: An analytical framework and initial empirical findings. Jtijdschrift voor economische en sociale geografie, 99(5), 528-546. TABLE 5Regression Analyses for the Fragmentation of Non-daily Shopping and Leisure Activities Non-daily shopping Number of episodes B Constant Mean episode size β 1.761*** B β 37.2*** Leisure Mean temporal distance between the episodes B β 72.6*** Mean temporal distance episode to its nearest neighbouring episode B β 57.3*** 0.010*** -14.8*** -0.185 -21.4* -0.132 -21.4** -3.8* 0.162* 0.698*** Urbanization level Workday 1.7* B β 160.7*** 0.106 0.191* 0.094 0.268*** -0.128 β 26.1 -0.127 0.206** B -36.0** -0.112 -26.4** -0.097 -5.8 2.6*** .203 2.2*** 0.189 90.3*** .220 64.4** 0.169 27.6** 0.138 -.162 -.131 0.083 0.430*** 0.039 459 β Mean temporal distance episode to its nearest neighbouring episode B Β 0.07 6 0.18 5 Commute by public transport Number of cars in household Picking up/bringing away two or more times R2 N B Mean episode size 1.889*** Age Two or more children under 12 years Gender Male High education Primary Internet use at work Number of days working from home Number of ICT devices owned Culemborg Number of episodes Mean temporal distance between the episodes 0.037 459 0.017 230 0.051 230 0.071 561 0.176 -51.8*** 0.054 561 -0.176 0.085 227 0.100 227 *p < 0.1; ** p < 0.05; *** p < 0.01 39