This paper explores how data serve as evidence for phenomena. In contrast to standard philosophical models which invite us to think of evidential relationships as logical relationships, I argue that evidential relationships in the context of data-to-phenomena reasoning are empirical relationships that depend on holding the right sort of pattern of counterfactual dependence between the data and the conclusions investigators reach on the phenomena themselves.

Especially troublesome in this dispute is the status of the natural sciences, and this is where Hacking finds some of his most telling cases, from the conflict ...

I offer an analysis of operationism in psychology, which is rooted in an historical study of the investigative practices of two of its early proponents (S. S. Stevens and E. C. Tolman). According to this analysis, early psychological operationists emphasized the importance of experimental operations and called for scientists to specify what kinds of operations were to count as empirical indicators for the referents of their concepts. While such specifications were referred to as “definitions,” I show that such definitions were (...) not taken to constitute a priori knowledge or be analytically true. Rather, they served the pragmatic function of enabling scientists to do research on a purported phenomenon. I argue that historical and philosophical discussions of problems with operationism have conflated it, both conceptually and historically, with positivism, and I raise the question of what are the “real” issues behind the debate about operationism. (shrink)

I provide a historical and philosophical analysis of the doctrine of operationism, which emerged in American psychology in the 1930s. While operationism is frequently characterized as a semantic thesis , I argue that it is better understood as a methodological strategy, which urges that scientific concepts have to be cast in a form that makes their referents amenable to experimental investigation. I present three historical case studies of the work of early proponents of operationism and show that all of them (...) were impressed by behaviorist critiques of traditional mentalism and introspectivism, while still wanting to investigate some of the phenomena of traditional psychology . I show that when these psychologists used "operational definitions", they posited the existence of particular psychological phenomena and treated certain experimental data---by stipulation ---as indicative of those phenomena. However, they viewed these stipulative empirical definitions as neither a priori true, nor as unrevisable. While such stipulative definitions have the function of getting empirical research about a phenomenon "off the ground", they clearly don't provide sufficient evidence for the existence of the phenomenon. In the philosophical part of my dissertation, I raise the epistemological question of what it would take to provide such evidence, relating this question to recent debates in the philosophy of experimentation. I argue that evidence for the existence of a given phenomenon is produced as part of testing descriptive hypotheses about the phenomenon. Given how many background assumptions have to be made in order to test a hypothesis about a phenomenon, I raise the question of whether claims about the existence of psychological phenomena are underdetermined by data. I argue that they are not. Lastly, I present an analysis of the scientific notion of an experimental artifact, and introduce the notion of an "artifactual belief", i.e. an experimentally well-confirmed belief that later turns out to be false, when one or more of the background assumptions turn out to be false. (shrink)