Date of Award


Degree Name

Doctor of Philosophy



First Advisor

Dr. Galen Alessi

Second Advisor

Dr. Howard Farris

Third Advisor

Dr. Lonnie Hannaford

Fourth Advisor

Dr. Jack Michael


The effect of inclusion of irrelevant stimuli on concept attainment was investigated. Six regular education and six special education subjects learned a total of nine nonsense concepts under three training conditions differing in the number of irrelevant features presented. No major differences in performance were noted to be dependent on training condition. Special Education subjects reached mastery in approximately twice as many trials as the Regular Education subjects. Once mastered, both groups demonstrated similar retention and response to novel examples. Special Education subjects showed little improvement over the nine concepts. Regular Education subjects showed great improvement and responded almost errorlessly on the last three concepts trained.

The results suggest that the inclusion of irrelevant stimulus information in concept tasks does not differentially affect performance and that the primary difference between the two subject groups was in the number of trials to mastery and effect of practice.

Access Setting

Dissertation-Open Access