Effects of Meaningful Stimuli Contained in Different Numbers of Classes on Equivalence Class Formation

Previous experiments have investigated the function of using pictures or meaningful stimuli on equivalence class formation. For example, when attempting to form three 5-member classes (A→B→C→D→E), findings have shown that pictures used as C stimuli have increased the probability of producing equivalence class formation relative to when all stimuli in the stimulus set are abstract. The present experiment extends the literature by examining whether the formation of equivalence classes varies as a function of having three (C1, C2, and C3), two (C1 and C2), or one (C1) stimulus as a picture in a set of abstract stimuli. Hence, 60 participants were randomly assigned to 4 different experimental groups: 0-picture group or abstract group (ABS), 1-picture group (1PIC), 2-pictures group (2PIC), and 3-pictures group (3PIC). In addition, we had a reference group with abstract shapes only. The findings from the present experiment showed that 2 of 15 participants in the ABS formed classes. Also, two of 15 participants in the 1PIC formed classes, 8 of 15 participants in the 2PIC formed equivalence classes, and 12 of 15 members in the 3PIC formed classes. The statistical analysis supported the notion that equivalence class formation is a function of the number of pictures in a potential equivalence class.