Chapter Nine Measurement & Scaling Chapter Objectives • Identify the four levels of measurement under which numbers generated through a survey can be classified. • Distinguish among attributes, behavioral variables, beliefs, and attitudes. • List and describe five methods for inferring people's attitudes. Copyright © Houghton Mifflin Company. All rights reserved. 9|2 Chapter Objectives (Cont’d) • Discuss the various dimensions on which rating scales can vary. • Apply the formats of Likert, semanticdifferential, and Stapel scales and discuss how data generated by these scales are analyzed and interpreted. • Define validity, reliability, and sensitivity of a scale. Copyright © Houghton Mifflin Company. All rights reserved. 9|3 Harris Interactive: U.S.Based Survey Reputation Score of Top Ten Corporations Copyright © Houghton Mifflin Company. All rights reserved. 9|4 Harris Interactive: U.S. Based Survey Six Dimensions of Reputation Emotional Appeal Financial Performance Products and Services Reputation Workplace Environment Vision and Leadership Social Responsibility Copyright © Houghton Mifflin Company. All rights reserved. 9|5 20 Attributes of the Six Dimensions Measured Using a 7 Point Scale • Emotional Appeal – Like – Respect – Trust • Workplace Environment – Well managed – Appealing workplace – Employee Talent Copyright © Houghton Mifflin Company. All rights reserved. 9|6 20 Attributes of the Six Dimensions Measured Using a 7 Point Scale (Cont’d) • Products and Services – – – – Innovative Strong brand Quality Value • Social Responsibility – Citizenship – Environmental stewardship – Ethics Copyright © Houghton Mifflin Company. All rights reserved. 9|7 Six Dimensions and Its Scales • Vision and Leadership – Clear values – Strong leadership – Inspiring vision • Financial Performance – – – – Growth prospects Past results Recognizes opportunities Low risk Copyright © Houghton Mifflin Company. All rights reserved. 9|8 Measurement • Measurement is “the assignment of numbers to observations [or responses] according to some set of rules” Copyright © Houghton Mifflin Company. All rights reserved. 9|9 Measurement Levels • • • • Nominal Ordinal Interval Ratio Copyright © Houghton Mifflin Company. All rights reserved. 9 | 10 Nominal-Scaled Responses • Numbers forming a nominal scale are no more than labels used solely to identify different categories of responses • Example: What is your sex? – Male – Female Copyright © Houghton Mifflin Company. All rights reserved. 9 | 11 Nominal-Scaled Responses (Cont’d) • Which one of the following media influences your purchasing decisions the most? – – – – – Television Radio Newspapers Magazines Internet Copyright © Houghton Mifflin Company. All rights reserved. 9 | 12 Central Tendency– Mode • The mode is the most frequent category only statistics applicable to nominal variable Copyright © Houghton Mifflin Company. All rights reserved. 9 | 13 Ordinal-Scaled Responses • An ordinal scale is more powerful than a nominal scale in that the numbers possess the property of rank order • How long do you spend reading newspapers on a typical weekday? – – – – Less than 5 minutes 5 minutes to less than 15 minutes 15 minutes to less than 30 minutes 30 minutes or more Copyright © Houghton Mifflin Company. All rights reserved. 9 | 14 Mode and Median • The mode and the median are the most meaningful measures of central tendency for ordinal-scaled responses • Median – the category in which the 50th percentile response falls when all responses are arranged from lowest to highest (or vice versa) Copyright © Houghton Mifflin Company. All rights reserved. 9 | 15 Consider the following distribution of responses to the question about reading newspapers • In this case, the mode is category 1, and the median is category 2. Response Category Percentage of Respondents Checking Category 1 40 2 25 3 25 4 10 Copyright © Houghton Mifflin Company. All rights reserved. 9 | 16 Interval-Scaled Responses • An interval scale has all the properties of an ordinal scale and the differences between the scale values can be meaningfully interpreted Copyright © Houghton Mifflin Company. All rights reserved. 9 | 17 Interval-Scaled Responses (Cont’d) • How likely are you to buy a new automobile within the next six months? (Please check the most appropriate category.) Will definitely not buy Extremely unlikely Unlikely Likely Extremely likely Will definitely buy Copyright © Houghton Mifflin Company. All rights reserved. _____ (1) _____ (2) _____ (3) _____ (4) _____ (5) _____ (6) 9 | 18 Exhibit 9.1 Impact of Arbitrariness of an Interval Scale’s Starting Point Copyright © Houghton Mifflin Company. All rights reserved. 9 | 19 Ratio-Scaled Responses • Ratio scales possess all the properties of an interval scale and the ratios of numbers on these scales have meaningful interpretations • What is your annual income before taxes? $______ • How far is your workplace from your home? _____ miles Copyright © Houghton Mifflin Company. All rights reserved. 9 | 20 Classes of Variables • • • • Attributes Behavior Beliefs Attitudes Copyright © Houghton Mifflin Company. All rights reserved. 9 | 21 Attitudes • Attitudes are similar to beliefs, except that they also involve respondents’ evaluative judgments • For instance, do respondents feel print advertisements for cigarettes should be banned? Copyright © Houghton Mifflin Company. All rights reserved. 9 | 22 Attitudes – Conceptually and Operationally • A conceptual definition of attitude may be “a predisposition to respond favorably or unfavorably to a stimulus object” • An operational definition of attitude refers to a person’s attitude towards a particular retail store that may be measured as the total of the person’s expressed degree of agreement, on a 5-point, “strongly agree” to “strongly disagree” scale, with each of a set of 20 evaluative statements about various aspects of the retail store Copyright © Houghton Mifflin Company. All rights reserved. 9 | 23 Attitude Scaling • Attitudes – Widely believed to be a key determinant of behavior – Can only be inferred and cannot be directly ascertained • Measures in which inferences are drawn from – – – – Observed overt behavior Individual's reaction Performance on objective tasks Physiological reactions Copyright © Houghton Mifflin Company. All rights reserved. 9 | 24 Observing Overt Behavior • Observation of overt behavior is useful when other attitude measurement methods are inconvenient or infeasible • An observation study can be used to ascertain the attitudes of very young children toward a variety of toys Copyright © Houghton Mifflin Company. All rights reserved. 9 | 25 Analyzing Reactions to Partially Structured Stimuli • Projective Techniques – The approach of analyzing reactions to partially structured stimuli involves asking respondents to react to or describe in some fashion, an incomplete, vague stimulus Copyright © Houghton Mifflin Company. All rights reserved. 9 | 26 Evaluating Performance on Objective Tasks • To evaluate performance on objective tasks, respondents are asked to complete an ostensibly objective, well-defined task • The nature of their performance is then analyzed to infer their attitudes Copyright © Houghton Mifflin Company. All rights reserved. 9 | 27 Monitoring Physiological Responses • Monitoring physiological responses is based on the premise that a person's emotional reactions to a stimulus will be accompanied by corresponding involuntary physiological changes Copyright © Houghton Mifflin Company. All rights reserved. 9 | 28 Self-report Measurements of Attitudes • This method involves asking respondents relatively direct questions concerning attitudes toward whatever is of interest to the researcher • The questions are typically in the form of rating scales on which respondents check off appropriate positions that best reflect their feelings Copyright © Houghton Mifflin Company. All rights reserved. 9 | 29 Graphic Formats • A graphic rating scale presents a continuum, in the form of a straight line, along which a theoretically infinite number of ratings are possible • Example: Indicate your overall opinion about eBay by placing a mark at an appropriate position on the line below. Very Bad Copyright © Houghton Mifflin Company. All rights reserved. Very Good 9 | 30 Itemized Formats • Itemized rating scales have a set of distinct response categories • Any suggestion of an attitude continuum underlying the categories is implicit • They essentially take the form of the multiplecategory questions Copyright © Houghton Mifflin Company. All rights reserved. 9 | 31 Comparative Assessments • Comparative Rating Scale – Provides all respondents with a common frame of reference – Allows the researcher to be confident that all respondents are answering the same question Copyright © Houghton Mifflin Company. All rights reserved. 9 | 32 Non-comparative Assessments • Non-comparative Rating Scale – Implicitly permits respondents to use any frame of reference or no frame of reference at all Copyright © Houghton Mifflin Company. All rights reserved. 9 | 33 Forced Response Choices • A forced-choice scale does not give respondents the option of expressing a neutral or middle-ground attitude Copyright © Houghton Mifflin Company. All rights reserved. 9 | 34 Forced Response Choices (Cont’d) Indicate your overall opinion about eBay by checking one of the following categories: Very Bad Bad [ ] [ ] [ ] 1 2 3 [ ] 4 Neither Bad Very nor Good Good Good [ ] [ ] [ ] [ ] [ ] 5 6 7 8 9 What is your overall rating of eBay in comparison with other auction sites? Much worse ( ) Worse About the same Better ( ) ( ) ( ) Copyright © Houghton Mifflin Company. All rights reserved. Much better ( ) 9 | 35 Non-forced Response Choices • A non-forced-choice scale give respondents the option to express a neutral attitude Copyright © Houghton Mifflin Company. All rights reserved. 9 | 36 Non-forced Response Choices (Cont’d) Indicate your overall opinion about eBay by placing a mark in the category that best summarizes your feelings. Very Bad [ ] [ ] 1 2 [ ] 3 [ ] 4 [ ] 5 [ ] 6 [ ] 7 Very Good [ ] [ ] 8 9 What is your overall rating of eBay in comparison with other auction sites? Much worse ( ) Worse ( ) Copyright © Houghton Mifflin Company. All rights reserved. Better ( ) Much better ( ) 9 | 37 Balanced Response Choices • A balanced scale is one that has an equal number of positive/favorable and negative/unfavorable response choices Copyright © Houghton Mifflin Company. All rights reserved. 9 | 38 Balanced Response Choices (Cont’d) Indicate your overall opinion about eBay by checking one of the following categories: Very Bad Bad [ ] [ ] [ ] 1 2 3 [ ] 4 Neither Bad Very nor Good Good Good [ ] [ ] [ ] [ ] [ ] 5 6 7 8 9 What is your overall rating of eBay in comparison with other auction sites? Much worse ( ) Worse About the same Better ( ) ( ) ( ) Copyright © Houghton Mifflin Company. All rights reserved. Much better ( ) 9 | 39 Unbalanced Response Choices • An unbalanced rating scale that can be used if respondents’ opinions about a subject are anticipated to be predominantly positive Copyright © Houghton Mifflin Company. All rights reserved. 9 | 40 Labeled Response Choices Copyright © Houghton Mifflin Company. All rights reserved. 9 | 41 Unlabeled Response Choices Copyright © Houghton Mifflin Company. All rights reserved. 9 | 42 Exhibit 9.2 Rating Scales with Picture Labels Copyright © Houghton Mifflin Company. All rights reserved. 9 | 43 Number of Scale Positions • A scale with a large number of positions will not be meaningful if respondents are unable to make fine mental distinctions with respect to whatever is being measured • More precise measurements should result as the number of scale positions increase Copyright © Houghton Mifflin Company. All rights reserved. 9 | 44 Paired Comparison Scale • In each of the following pairs, which store do you think is better? (please check one online auction site within each pair) _______ Amazon or_______ eBay _______ eBay or _______ Yahoo! Auction _______ PriceLine.com or _______ eBay _______ eBay or _______ Ubid.com Copyright © Houghton Mifflin Company. All rights reserved. 9 | 45 Commonly Used Multiple-item Scales • Likert Scale • Semantic-Differential Scale • Stapel Scale Copyright © Houghton Mifflin Company. All rights reserved. 9 | 46 Table 9.2 Likert Scale Items 1. 2. 3. 4. 5. 6. Strongly Disagree Disagree Neither Agree nor Disagree Agree Strongly Agree The online auction site contains an abundance of exhibits ________ ________ ________ ________ ________ User registration is complex at this site ________ ________ ________ ________ ________ The auction site commission is reasonable ________ ________ ________ ________ ________ The auction site responds to complaints quickly ________ ________ ________ ________ ________ The auction site is not careful with personal information ________ ________ ________ ________ ________ The auction site support system is confusing ________ ________ ________ ________ ________ Copyright © Houghton Mifflin Company. All rights reserved. 9 | 47 Exhibit 9.3 Semantic-Differential Scale Items Copyright © Houghton Mifflin Company. All rights reserved. 9 | 48 Exhibit 9.4 Pictorial Profiles Based on Semantic-Differential Ratings Copyright © Houghton Mifflin Company. All rights reserved. 9 | 49 Table 9.3 Stapel Scale Abundanc e of Exhibits Complex User Registration Low Commission Good Response to Complaints Poor Protection of Personal Information Confusing Support System +5 +5 +5 +5 +5 +5 +4 +4 +4 +4 +4 +4 +3 +3 +3 +3 +3 +3 +2 +2 +2 +2 +2 +2 +1 +1 +1 +1 +1 +1 -1 -1 -1 -1 -1 -1 -2 -2 -2 -2 -2 -2 -3 -3 -3 -3 -3 -3 -4 -4 -4 -4 -4 -4 -5 -5 -5 -5 -5 -5 Copyright © Houghton Mifflin Company. All rights reserved. 9 | 50 Strengths Of Multiple-Item Scales • Validity • Content validity • Construct validity • Predictive validity • Reliability • Test-retest reliability • Split-half reliability • Sensitivity Copyright © Houghton Mifflin Company. All rights reserved. 9 | 51 Validity • The validity of a scale is the extent to which it is a true reflection of the underlying variable it is attempting to measure Copyright © Houghton Mifflin Company. All rights reserved. 9 | 52 Content Validity • Face validity or content validity is the extent to which the content of a measurement scale seems to tap all relevant facets of an issue that can influence respondents’ attitudes Copyright © Houghton Mifflin Company. All rights reserved. 9 | 53 Exhibit 9.5 Types of Equivalence Copyright © Houghton Mifflin Company. All rights reserved. 9 | 54 Construct Validity • Construct Validity is the nature of the underlying variable or construct measured by the scale Copyright © Houghton Mifflin Company. All rights reserved. 9 | 55 Predictive Validity • Predictive Validity refers to how well the attitude measure provided by the scale predicts some other variable or characteristic Copyright © Houghton Mifflin Company. All rights reserved. 9 | 56 Reliability • Reliability measures how consistent or stable the ratings generated by the scale are likely to be Copyright © Houghton Mifflin Company. All rights reserved. 9 | 57 Test-Retest Reliability • Test-Retest Reliability measures the stability of ratings over time and involves administering the scale to the same group of respondents at two different times Copyright © Houghton Mifflin Company. All rights reserved. 9 | 58 Split-Half Reliability • Split-Half Reliability measures the degree of consistency across items within a scale and can only be assessed for multiple-item scales Copyright © Houghton Mifflin Company. All rights reserved. 9 | 59 Sensitivity • Sensitivity focuses specifically on its ability to detect subtle differences in the attitudes being measured Copyright © Houghton Mifflin Company. All rights reserved. 9 | 60