Chapter 9 Abstract

 

The aim of this chapter is to build on the knowledge and experiences that have been developed over the preceding eight chapters and prepare the reader to embark on further studies about measurement. To that end, three topics that have arisen during the previous chapters but which were put aside in the interests of making progress on the main thrust of the book will be enlarged upon. Specifically, each of the following topics is discussed in this chapter.

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(a) First, what calibration model should the measurer choose? There are many candidate models, and one cannot try out every possibility, so some “in principle” decisions must be made. A discussion of the most important principles involved in this decision follows, along with some illustrations of why this matters.

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(b) Second, how can one examine the empirical evidence for one calibration model versus another? Is it just matter of testing for statistical significance, or is there more to it than that?

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(c) Third, what can be done when the situation involves the measurement of multiple constructs at the same time—commonly called “multidimensionality.” How can the calibration model used in this book be broadened to take advantage of this richer interpretation?