Discussion Questions and Topics (4). Measurement and Scaling. Terms to know. Operational definition Measurement of constructs Scaling types as tools: Nominal Ordinal Interval Ratio. What are the sources of variation in measured score?. True differences
Discussion Questions and Topics (4) Measurement and Scaling
Terms to know • Operational definition • Measurement of constructs • Scaling types as tools: • Nominal • Ordinal • Interval • Ratio
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
Comment and Prove • If a measure is valid, then it is reliable. • X0=XT+XS+XR • XO= Observed Score • XT= True Score • XS= Systematic Error • XS= Random Erro
How doyou infer validity of a measure? • Indirect Evidence by reliability • Where XR=0 • Direct evidence by validity • Where XO=XT • Domain Sampling Model
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
What is the procedure for scale development? • Let’s look at Consumer Discontent Scale and identify the steps in developing this scale?