Date of Degree


Document Type


Degree Name





Lanny Fields

Subject Categories

Education | Psychology | Social and Behavioral Sciences


card sorting, conditional discriminative functions, equivalence class formation, meaning, simultaneous protocol


Two experiments explored how the formation of two 3-node, 5- member equivalence classes by college students was influenced by the prior acquisition of conditional discriminative functions by one of the abstract stimuli, designated as C, in the class. In Experiment 1, participants in the GR-0, GR-1, and GR-5 groups attempted to form classes after mastering 0, 1 or 5 conditional relations between C and abstract stimuli that were not included in the to-be-formed classes. Participants in the GR-many group attempted to form classes that contained four abstract stimuli and one meaningful, familiar picture that served as the C stimulus. In Experiment 1, the percentage of participants who formed classes in the GR-0, -1, and -5 groups was a direct function of the number of conditional relations that C formed with other stimuli in preliminary training, with the GR-5 group producing a yield similar to that produced when a meaningful picture was the C stimulus (i.e., in the GR-many condition). Two factors differentiated GR-1 and GR-5 pre-training: the number of conditional relations trained to C, and the number of training trials in the presence of the C stimuli. Experiment 2 found that the increase in yield produced by GR-5 was due to number of trained C-based relations and not to the amount of training. Furthermore, Experiment 2 showed that enhancement of class formation after GR-1 pre-training is not improved by linking the C stimulus with a meaningful picture instead of a meaningless stimulus. These results along with recently published research support the view that the class enhancing effect of meaningful stimuli can be attributed to their acquired conditional discriminative and simple discriminative functions, in addition to their connotative and denotative functions.



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