Design, Evaluation, and Analysis of Questionnaires for Survey Research, 2nd Edition

14

THE QUALITY OF MEASURES FOR CONCEPTS-BY-POSTULATION

In this chapter, we pick up the discussion of the first chapter about concepts-by-postulation (CP) and concepts-by-intuition. This is important because often, the concepts people want to study are not so simple that they can be operationalized by concepts-by-intuition. Several concepts-by-intuition are also combined into one CP in order to obtain a measure of the concept of interest with better reliability and/or validity. To date, we have become familiar with the quality of measures for concepts-by-intuition. In this chapter, we want to show how this information can be used to say something about the quality of measures for CP. This is possible because a measure of a CP is an aggregate of several measures of concepts-by-intuition.

First, we will introduce the possible structures of CP. The logic is that the measures of CP are based on concepts-by-intuition. In order to determine the score of the CP, the relationships between the concepts-by-intuition and the CP need to be known. In some cases, one can control whether the expected relationships indeed exist. Depending on the hypothesized relationships, different tests for the structure of the measures are performed. In this chapter, we will discuss these different structures and indicate how the quality of the measures for the CP can be determined on the basis of the estimated quality of the measures for the concepts-by-intuition.

14.1 THE STRUCTURES OF CONCEPTS-BY-POSTULATION ...