Stimulus equivalence: Conceptual and methodological issues

Article 1: The research field of concepts is—in the present article—divided in two accounts: the cognitive psychology approach and the behavior analysis approach. The article starts off by illuminating the philosophical assumptions related Pepper’s (1942) world hypothesis, or worldviews, restricted to mechanism and contextualism. Later, there are drawn analogies between the worldviews and the scientific practices of cognitive psychology and behavior analysis. With respect to cognitive psychology, main characteristics of three of the theories of the structural study of concepts will be described. With respect to behavior analysis, the study of variables influencing concept formation, and stimulus equivalence, will be presented with links drawn to the early work of Murray Sidman on conditional discrimination training. The conclusion of the article will consist of some suggestions of systematic replications that are needed with respect to earlier research on the measurement of equivalence class formation. The article will end by pinpointing the general purpose of Article 2. Article 2: The purpose of the present experiment is to provide data on the aspects of the concordance between the Matching-to-Sample test and the sorting test. In the present study, 20 college students were divided into two order-controlled groups. Group 1-participants were exposed to an immediate sorting test after training of baseline relations, followed by the administration of a Matching-to-Sample (MTS) test, and another sorting test. Group 2-participants were exposed to an immediate MTS test after training of the baseline relations, followed by a sorting test and a readministration of the MTS test. The results show systematic replication of earlier findings with respect to concordance between the tests, dissociation in some cases, and approached performances (i.e., one or two, of three possible, classes established). However, based on the experimental design of the present experiment, we are able to more effectively discuss the role of equivalence classes in relation to the sorting test outcome. The assumption that one can document equivalence classes by the sorting test alone is rejected with data in the present experiment