Chapter 4 - The Measurement of Chronometric Variables

Abstract

This chapter presents the measurement of chronometric variables such as psychophysics, psychometrics, and chronometrics. The greatest problem in psychometrics is the measurement properties of test scores, even when all of the most sophisticated methods of test construction have been rigorously applied. The problem is the uncertain nature of the relationship between the metric of the obtained test scores and the metric of the latent trait the test is assumed to measure. The chapter explains the basic problems that can be understood in terms of three types of measurement scales—ordinal, interval, and ratio. They differ in the amounts of information they convey that limits the kinds of conclusions they can support. A measurement methodology based on a set of mathematical models of the relationship between item difficulty and ability also called latent trait theory, attempts to overcome the main limitations of classical test theory in which the quantitative interpretation of multi-item test scores is entirely dependent on the ability levels encompassed by a particular reference group.