On the Role of Sorting

A few studies have been done with focus on sorting or categorization tests as part of the method within stimulus equivalence research (see for example Fields, Arntzen, Nartey, & Eilifsen, 2012). The sorting test can be accomplished in a few minutes compared to about 30 to 40 minutes in the stimulus equivalence test. The research question in the present study was to explore the role of sorting as an alternative goal on stimulus equivalence compared to the standard tests for stimulus. The participants were adults, 21 to 41 years of age. We employed a linear series (LS) structure to establish three 5-member classes. All participants were exposed to a first phase, which included a sorting test. In the second phase, training was arranged as conditional discriminations in a traditional MTS format. Then, the participants were tested for equivalence class formation. In the third phase, an identical sorting test as in the first phase was presented. Dependent on the outcome of the second and third phase, the participants went through to a new phase with a new stimulus set or a re-test of both sorting and the test for stimulus equivalence with the same stimulus set. The data was analyzed to see if there was any coherence between the sorting test and the establishment of emergent relations.