Measurement and Scaling

1. Measurement and Scaling • Terms to know • Discussion questions and topics (4)

2. Measurement and Scaling • Operational Definitions • Measuring Constructs • Types of Scales • Discussion Questions and Topics (4) • Development of Scales • Example: Consumer Discontent Scale

3. Operational Definition • Stating a construct in terms of its dimensions and elements so that it becomes measurable. • Examples: Learning Stress

4. MEASUREMENT • Assignment of numbers to the characteristics of objects, people,states, or events according to rules. • Numbers • Characteristics of objects, etc. • Rules

5. Assessing a Respondent’s Liking of Soft Drinks With Nominal, Ordinal, Interval, and Ratio Scales Nominal Which of the soft drinks in the following list do you like? (Check ALL that apply): ___Coke ___Dr. Pepper ___Mountain Dew ___Pepsi ___Seven Up ___Sprite Ordinal Rank the soft drinks according to how much you like each (most preferred drink = 1, and least preferred drink = 6): ___Coke ___Dr. Pepper ___Mountain Dew ___Pepsi ___Seven Up ___Sprite Interval Please indicate how much you like each soft drink by checking the appropriate position on the scale: dislike like a lot dislike like a lot Coke ____ ____ ____ ___ Dr. Pepper ____ ____ ____ ___ Mountain Dew ____ ____ ____ ___ Pepsi ____ ____ ____ ___ Seven Up ____ ____ ____ ___ Sprite ____ ____ ____ ___ Ratio Please divide 100 points among these soft drinks To represent how much you like each: ___Coke ___Dr. Pepper ___Mountain Dew ___Pepsi ___Seven Up ___Sprite 100

6. Paired Comparison Scale(ordinal) • The brands to be rated are presented two at a time, so each brand in the category is compared once to every other brand • Compare Nestle with Milka Nestle with Eti Milka with Eti

7. Likert Summated Rating Form (interval) neither strongly agree nor strongly disagree disagree disagree agree agree • The bank offers courteous service. ___ ___ ___ ___ ___ • The bank has a convenient location. ___ ___ ___ ___ ___ • The bank has convenient hours. ___ ___ ___ ___ ___ • The bank offers low interest rate loans. ___ ___ ___ ___ ___

8. Semantic Differential Scaling Form (interval) Service is discourteous ___:___:___:___:___:___:___ Service is courteous Location is convenient ___:___:___:___:___:___:___ Location is inconvenient Hours are convenient ___:___:___:___:___:___:___ Hours are inconvenient Loan interest rates are high ___:___:___:___:___:___:___ Loan interest rates are low

9. Contrasting Profiles of Banks A and B (derived from semantic differential scale) Service is discourteous ___:___:___:___:___:___:___ Service is courteous Location is convenient ___:___:___:___:___:___:___ Location is inconvenient Hours are convenient ___:___:___:___:___:___:___ Hours are inconvenient Loan interest rates are high ___:___:___:___:___:___:___ Loan interest rates are low Bank A Bank B

10. Comparative Judgement Scale (interval) • Compared to Signal, Colgate’s whitening power is: • Much better • Better • About the same • Worse • Much worse

11. Graphic Rating Scale (ratio) Please evaluate each quality in terms of how important it is to you personally by clicking the cursor at the position on the horizontal line that most reflects your feelings: not very important important Courteous service _______________________________________ Convenient location _______________________________________ Convenient hours _______________________________________ Low interest rate loans _______________________________________

12. Constant Sum Scale (ratio) Please divide 100 points among the following bank services in terms of relatively how important each is to you: ___Courteous service ___Convenient hours ___Convenient location ___Low interest rates 100

13. Sad-to-Happy Faces that Work with Children (and Adults!)

14. Discussion Questions and Topics (4) Measurement and Scaling

15. Terms to know • Operational definition • Measurement of constructs • Scaling types as tools: • Nominal • Ordinal • Interval • Ratio

16. What are the sources of variation in measured score? • True differences • Stability in individual characteristics • Transient factors • Situational Factors • Variations in administration • Sampling of items • Clarity of measurement instrument • Mechanical factors

17. Comment and Prove • If a measure is valid, then it is reliable. • XO=XT+XS+XR • XO= Observed Score • XT= True Score • XS= Systematic Error • XS= Random Erro

18. How doyou infer validity of a measure? • Indirect Evidence by reliability • Where XR=0 • Direct evidence by validity • Where XO=XT • Domain Sampling Model

19. Indirect Evidence Via Reliability Coefficients Direct Evidence Via Validity Coefficients Test-retest Alternate forms Split half Coefficient  Predictive validity Content validity Construct validity Convergent validity Discriminant validity

20. What is the procedure for scale development? • Let’s look at Consumer Discontent Scale and identify the steps in developing this scale?

21. The Development of a Scale to Measure Consumer Discontent William J. Lundstrom Lawrence M. Lamont Journal of Marketing Research, Nov. 1976

22. Procedure for Scale Development 1. Definition of the construct and development of scale statements 2. Selection of the type of scaling procedure 3. Selection of items for testing of scale properties 4. Reliability testing of scale properties 5. Validation of final scale properties

23. Step1: Definition of the Construct and Development of Scale Statements • Comprehensive literature review • Scope of consumer discontent • The product strategies of business • Business communications and information • Impersonal nature of business & retail institutions • Socioeconomic and political forces

24. Definition of the Construct and Development of Scale Statements Initial Item Pool Edited Item Pool Preliminary Form of the Scale 173 Statements 118 Statements 99 Statements 10 Judges

25. Scaling Procedure • Likert-type scales (Summated Ratings) • Six-point interval scaled from “strongly agree” to “strongly disagree” • Total attitude score for each respondent

26. Item Analysis and Selection • Assessing an item’s ability to differentiate significantly between subjects • 99 statements, 309 respondents • t-test • Respondents’ summated item scores (highest to lowest) • Highest 25% and lowest 25% used as criterion groups • Determining statements showing a statistically significant difference • 84 items retained for reliability testing

27. Validity Testing • Construct Validity • Internal validity analysis • Scale homogeneity and consistency • Correlation of each statement with the total score • Final version of the scale - 82 items • External validity analysis • Whether scale score could distinguish between 'known groups’ of persons holding different attitudes • Sample: Contended group (100) & discontended group (180) • z-test - significant difference between two groups

28. Reliability Testing • Test Reliability (226 subjects) • Split-half – internal consistency • Split-half reliability coefficient (uncorrected) - .96 (Flanagan formula) • Split-half reliability coefficient (corrected) - .94 (Spearman-Brown prophecy formula) • Test-retest – temporal accuracy • Test-retest reliability coefficient - .79

29. Reliability Testing • Response Bias Reliability (226 subjects) • Agreement response scale (Couch & Kenniston) • Social desirability scale (Crowne & Marlowe) • Consumer discontent measure is not affected by respondent tendencies to answer in an acquiescent or socially desirable manner

30. Consumer Discontent Scale • Scale name and composition • Name: only one pole of bipolar construct • Composition: Negative response bias • Use of the scale • Self report scale • Respondent’s total score = sum (or mean) of the scores across statements