Psychometrics is one of the main approaches to social scientific measurement. It is relied upon in drug testing, economic policymaking, recruitment, and other decision-making contexts. The first aim of this article is to introduce philosophers to key aspects of psychometrics, namely, classical test theory, item response theory, and construct validity. The second aim is to show how a debate on the nature of psychological attributes manifests in psychometrics. In this debate, realists claim that psychometric measures are indicators of independently existing (...) qualities, while operationalists argue that a measure defines its target attribute. The third and final aim is to argue that despite its poor reputation among philosophers, operationalism is a viable approach to psychometrics. (shrink)

The Preface Paradox has led many philosophers to believe that, if it isassumed that high probability is necessary for rational acceptability, the principleaccording to which rational acceptability is closed under conjunction (CP)must be abandoned. In this paper we argue that the paradox is far less damaging to CP than is generally believed. We describe how, given certain plausibleassumptions, in a large class of cases in which CP seems to lead tocontradiction, it does not do so after all. A restricted version (...) of CP canthus be maintained. (shrink)

Despite influencing the social sciences since the 1930s, S. S. Stevens' "operationist" philosophy of science has yet to be adequately understood. I reconstruct Stevens' operationism from his early work and assess the influence of various views (logical positivism, behaviorism and the "operational viewpoint" of P. W. Bridgman, among others) on Stevens. Stevens' operationism emerges, on my reconstruction, as a naturalistic methodological directive aimed at agreement, founded in turn on the belief that agreement is constitutive of science, the scientific community, and (...) objectivity. Further, I show that operationism is historically and philosophically independent of the views mentioned above. (shrink)

This paper applies conceptual engineering to deal with four objections that have been levelled against operationalism in psychology. These objections are: operationalism leads to harmful proliferation of concepts, operationalism goes hand-in-hand with untenable antirealism, operationalism leads to arbitrariness in scientific concept formation, and operationalism is incompatible with the usual conception of scientific measurement. Relying on a formulation of three principles of conceptual engineering, I will argue that there is a useful form of operationalism that does not fall prey to these (...) four objections. (shrink)

With S.S. Stevens, operationism became an important influence in psychology. In this paper I discuss the differences between Bridgman's and Stevens' proposals on operationism and the role that operational definitions play in scientific theory. I discuss how Stevens' notions of the basic act of discrimination and of the relation procedure–outcome influenced B.F. Skinner's criteria under which the main conceptual distinctions in operant psychology were formulated. The operational origin of the dichotomies between respondent and operant behavior, contingency-shaped and rulegoverned behavior, private (...) and public events, and verbal and nonverbal behavior are examined. (shrink)