While recommendations concerning reinforcement strategies in vocational training of retarded persons range from the use of minimal social reinforcement to the use of extra social and edible reinforcement, empirical comparisons of such strategies could not be found in the literature. Four experiments were conducted to compare minimal social reinforcement to social plus edible reinforcement while lower functioning retarded clients were taught assembly tasks of varying complexities. In all experiments, the extra reinforcement generally facilitated the learning of a task to criterion in terms of training time, number of trials, total number of errors, and the proportion of errors on learned steps. Moreover, a preference test showed that the majority of clients preferred the extra reinforcement condition.
