Date of Award


Degree Name

Master of Arts



First Advisor

Dr. Wayne Fuqua

Second Advisor

Dr. Dick Malott

Third Advisor

Dr. Al Poling

Access Setting

Masters Thesis-Open Access


Overselective stimulus control occurs when behavior fails to come under control of all characteristics of a compound stimulus after discrimination training. The efficacy of two procedures designed to eliminate overselective stimulus control observed with six trainable mentally retarded children was compared in Experiment 1. A training procedure using S-'s which were minimally different from the S+ was designed to reduce the probability that stimulus discriminations could be based on stimulus characteristics othre than experiimenter specified characteristics defining the S+. This procedure proved more effective in preventing and eliminating overselective stimulus control than an alternate discrimination training procedure. Experiment 2 indicated that these improvements in stimulus control were not a function of varying degrees of difficulty between stimulus sets or of a prior history of discrimination training with the less effective procedure. The need for between assessment procedures to detect overselective stimulus control and suggestions for further improvements in discrimination training procedures are discussed.