1. INDEXES, SCALES, & TYPOLOGIES
COMPOSITE SCORES
INDEXES, SCALES, & TYPOLOGIES

2. WHY USE COMPOSITE SCORES
May not be a “clear” single indicator
Offers an increase in variability
Makes the analysis of data more “efficient”

3. Index or Scale Index Scale
Most “common”
Cumulative score (perform mathematical operation
Scale
Assign values to a “pattern” of responses (note: not all items are “equal”
Note: both indexes and scales are rank-order composite measures

4. Index Construction Item Selection Scoring Empirical Examination
Face validity
Unidimensionality
General vs Specific
Variability
Scoring
Variability vs “Adequate number of cases in categories
Item weighting (equal/unequal) in the index
Empirical Examination
Bivariate vs Multivariate
Missing Data
Validation

5. Scales and Scaling Empirically based Intensity of particular items
Responses are “scaled (not the survey questions/items
Intensity of particular items
Is there a pattern in how the items tap a concept?

6. Scale Construction Not all items are “equal” Examples:
“intensity structures” among items
assurance of “ordinality”
Examples:
Thurstone Scale
Bogardus Social Distance Scale
Likert Scale
Semantic Differential
Guttman Scale

7. Typologies
Researcher can summarize the “overlap/intersection of two or more variables
Typically driven by some combination of “theory” and “data”
Life-course criminality
Probation example
Difficult to use a typology as the dependent variable
Question: why do particular cases “fit” in a particular typology (predicting typologies)

8. Using SPSS to Create an Index
Locate the data file
Identify the variables
Define the “New Variable”
Define the “mathematical operation”
Select “Transform”
Select “Compute”
Enter commands
Save file

9. Characteristics of Items
Recoding of some items may be necessary
Not all items (statements/questions) are in the same “direction”
Managing missing data
“Don’t Know” is problematic

10. Verification of Composite Scores
Factor Analysis
Reliability Coefficient
Item-Item Correlation
Item-Total Correlation