Carl Sundberg

Date of Award


Degree Name

Master of Arts



First Advisor

Dr. Jack L. Michael

Second Advisor

Dr. Alyce Dickinson

Third Advisor

Dr. R. W. Farqua

Access Setting

Masters Thesis-Open Access


This study examined whether it was easier for developmentally disabled individuals to acquire a topography-based or a selection-based language system. Four moderately and mildly mentally retarded adults served as subjects. Each of the subjects was taught to tact an object by either pointing to its corresponding symbol (with the selection-based paradigm) or making the corresponding sign (with the topography-based system). They were then taught an intraverbal relation by either selecting the symbol, or making the sign which corresponded to an auditory stimulus. Finally, the subjects were tested for the emergence of stimulus equivalence classes. Each subject was trained and tested with one paradigm, and then trained and tested with the other. The results show that sign language was acquired more easily than symbol board language, as measured by the acquisition of tacts, intraverbals, and the formation of stimulus equivalency.