The Complementarity of Psychometrics and the Representational Theory of Measurement

Abstract

Psychometrics and the representational theory of measurement (RTM) are widely used in social scientific measurement. They are currently pursued largely in isolation from one another. I argue that despite their separation in practice, RTM and psychometrics are complementary approaches, because they can contribute in complementary ways to the establishment of what I argue is a crucial measurement property, namely, representational interpretability. Because RTM and psychometrics are complementary in the establishment of representational interpretability, the current separation of measurement approaches is unfounded. 1Introduction2Two Approaches to Measurement 2.1Representational theory of measurement2.2Psychometrics2.3Representational interpretability3Complementarity, Conceptually 3.1Representational theory of measurement: Conditions of representational interpretability3.2Psychometrics: Evidence of representational interpretability4Complementarity in Action 4.1What is the Rasch model?4.2Rasch and conjoint measurement5Conclusion: Critics and Fruits of Complementarity

Operationalism and realism in psychometrics

“…Classical test theory has been criticized from various angles (Vessonen, , section 2.5) . Several critics have focused on the close connection between CTT and operationalism.…”

“…But philosophers are now getting up to speed, perhaps motivated by growing interest in general philosophy of measurement (Cartwright, Bradburn, & Fuller, ; Heilmann, ; Tal, ). By 2019, we have a handful of philosophical analyses of psychometrics in the science of well‐being (Alexandrova, , ; Angner, ), interpretations of psychometrics in terms of the realism/anti‐realism dichotomy (Hood, ), comparisons of psychometrics and the representational theory of measurement (Angner, ; but see also Suppes & Zinnes, ; Vessonen, , ), studies of the role of modelling in psychometrics (McClimans, Browne, & Cano, ; Peterson, ), and more general analyses of psychometrics as an epistemic activity (Alexandrova & Haybron, ).…”

“…There are multiple notions of construct validity in the literature (for a review, see Vessonen, , sections 2.6.2 and 2.6.3. )…”

“…It is likely that operationalists and realists could use the same psychometric tools in their measure validation, although they would have to interpret the results in different ways. See Vessonen (, Chapter 6) for a sketch of this view.…”

Respectful operationalism

“…Concepts that embody these shared values are likely to attract wider acceptance and outlive arbitrary concepts. Second, although the definition of a concept is not a matter of truth (see Carnap, 1950a, 1950b; I defend this view in Vessonen, 2019b), our capacity to define more useful concepts depends on uncovering truths about the denotation of that concept. 17 For example, if we establish that a particular IQ test does not correlate with real-world problem-solving skills, we can use that fact to evaluate the usefulness of the concept the IQ test defines.…”