Chapter 6 Indexes Scales and Typologies Scaling and

Chapter 6 Indexes, Scales, and Typologies

Scaling and Index • Constructed by accumulating scores assigned to individual attributes. • Examples • • • Conservatism Racism Political Activity

Scaling and Index • • You end up with a “score”. It is an ordinal measures of variables. It rank order units of analysis in terms of specific variables. Its measurements are based on more than one data item.

Selecting Items Criteria • Face (logical) validity • Unidimensionality • General or specific • Variance

Empirical Relationships • • Established when respondents’ answers to one question help predict how they will answer other questions. If two items are empirically related, we can argue that each reflects the same variable, and both can be included in the same index.

Assign Scores for Responses Two basic decisions: • Decide the desirable range of the index scores. • Decide whether to give each item in the index equal weight or different weights.

Ways to Handle Missing Data • • • Exclude cases with missing data from the construction of the index and the analysis. Treat missing data as one of the available responses. Analyze missing data to interpret the meaning.

Validate the Scale/Index • • Item Analysis - internal validation. External validation - ranking of groups on the index should predict the ranking of groups in answering similar or related questions.

Techniques of Scale Construction • • Likert scaling - uses standardized response categories. Semantic differential -asks respondents to rank answers between two extremes.

Typologies • • The classification (typically nominal) of observations in terms of their attributes on two or more variables. The classification of newspapers as liberal -urban, liberal-rural, conservative-urban, or conservative-rural would be an example.