The study examined the effectiveness of enhancing perceptual differentiation in the training of four developmentally delayed preschool children who were so low-functioning that they did not demonstrate oddity responding (ability to choose one distinct stimulus from a group of identical stimuli). Instead of the Arabic numerals used in the original…

This paper describes the Assessment of Basic Learning Abilities Test and recommends its use to assess discrimination acquisition or learning-to-learn skills of persons with severe and profound disabilities. (DB)