Saigh, P. A., & Payne, D. A. (1979). The effect of type of reinforcer and reinforcement schedule on performances of EMR students on four selected subtests of the WISC-R . Psychology in the Schools , 16 (1), 106–110. https://doi.org/10.1002/1520-6807(197901)16:1<106::AID-PITS2310160119>3.0.CO;2-R

Three reinforcement categories were employed: tokens, verbal praise, and verbal neutral. Participants in each of these three categories were randomly assigned to two schedule categories, fixed-ratio and continuous reinforcement.

The study included 120 institutionalized children (equal numbers of males and females) with mild intellectual disabilities (formerly "educable mental retardation"). The mean IQ was 65.3, and the mean age was 11.8 years.

The Arithmetic, Digit Span, Picture Completion, and Block Design subtests of the WISC-R Intelligence Test were administered.

The overall analysis of variance tests for the type of reinforcer groups were significant for the Arithmetic, Digit Span, and Picture Completion subtests. A subsequent ScheffT post-hoc test revealed a significant difference in mean scaled scores for both the verbal praise and token groups relative to the verbal neutral group. There was no main effect for type of reinforcer with the Block Design scores. None of the analyses for a main effect due to level of reinforcement schedule were statistically significant.