33 articles spanning SO yrs. of research on the effects of praise and blame on the performance of school children are reviewed. Praise generally acts as a facilitator to performance, though often it is indistinguishable from practice effect. The single exception in recent years is the decrement in performance from praised underachievers. Exceptions to the generally decremental effect of blame on the performance of children are underachieving children, very bright adolescents, and Negro children working under Negro examiners. The problem of subject-reinforcement history is presented as a major contributor to the confusion in the literature, and the use of functional designs is suggested as a solution.