Document Type


Degree Name

Master of Arts (MA)




Faculty of Science

First Advisor

Not applicable

Advisor Role

Not applicable


The effects of two stimulus-response durations (2 and 5 seconds) on performance in a paired-associate learning (PAL) task was assessed. The 3 x 3 x 2 design also permitted a comparison of the effects of rehearsal, mediated interference and the differential performance of normals and non-institutionalized and institutionalized retardates (n = 30, mean age = 12.6). The retarded groups were further matched on I.Q. scores on three factors of the Adaptive Behavior Scales (ABS). The stimuli were conceptually related, black and white, line drawn pictures of common objects. The results were twofold: a facilitating effect for increased S-R duration which could not be attributed to either rehearsal or mediation. Also the groups differed significantly in mean number of errors in the order: normals, institutionalized and non-institutionalized retarded. This study implies the need for greater specificity in selecting retarded subjects for comparative purposes.

Convocation Year