Many everyday matching tasks taught to persons with developmental disabilities are visual-visual non-identity matching (VVNM) tasks, such as matching the printed word DOG to a picture of a dog, or matching a sock to a shoe. Research has shown that, for participants who have failed a VVNM prototype task, it is very difficult to teach them various…

Fifty-one severely retarded adults were taught a difficult visual discrimination in an assembly task by one of three training techniques: (a) adding and reducing large cue differences on the relevant-shape dimension; (b) adding and fading a redundant-color dimension; or (c) a combination of the two techniques. (Author)