Chapter 6 Indexes, Scales, And Typologies

1
Chapter 6Indexes, Scales, And Typologies

• Index Construction
• Scale Construction
• Typologies

2
Index and Scale

• Similarities
• Both are ordinal measures of variables.
• Both rank order units of analysis in terms of
  specific variables.
• Both are measurements based on more than one data
  item.

3
Index and Scale

• Scoring Differences
• Index accumulate scores assigned to individual
  attributes.
• Scale assign scores to patterns of responses.

4
Constructing an Index

• Select items for a composite index.
• Examine empirical relationships.
• Assign scores for responses.
• Handle missing data.
• Validate the index.

5
Selecting Items

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

6
Examine Empirical Relationships

• Empirical relationships are established when an
  answer to one question helps predict the answers
  to other questions.
• Bivariate relationships - two variables
• Multivariate relationships - more than two
  variables

7
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.

8
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.

9
Validate the 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.

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Techniques of Scale Construction

• Bogardus social distance scale - measures the
  willingness of people to participate in social
  relations.
• Thurstone scales - judges determine the intensity
  of different indicators.

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Techniques of Scale Construction

• Likert scaling - uses standardized response
  categories.
• Semantic differential -asks respondents to rank
  answers between two extremes.
• Guttman scaling - uses an empirical intensity
  structure (most common).