This study compared the total amount of training time and total number of trial blocks for individuals with severe developmental disabilities to acquire mands under control of unconditioned establishing operations and mands under control of transitive conditioned establishing operations for manual sign and for the Picture Exchange Communication…

This study of four moderately to severely aphasic subjects found that success in manual sign training programs is related to severity of aphasia, that aphasic subjects' propositional use of manual signs rarely follows simple acquisition, and that generalization to untrained stimuli or environments does not occur without additional training.…

Four adults with moderate/severe disabilities were taught to request objects by using the manual signs "want" or "please" plus an object label sign, within the context of familiar activities in which needed objects were missing. All participants acquired a generic requesting response, and three acquired an explicit requesting…