Laboratory research was reviewed that compared the effects of various types (verbal, symbolic, tangible) and combinations (right-wrong, right-blank, wrong-blank) of feedback upon children's conceptual learning. This research was evaluated in terms of theories involving reinforcement, motivation, and information-processing interpretations. In general, the findings have been consistent in two respects: (I) Verbal and symbolic feedback produce more rapid acquisition than does tangible feedback. (2) The wrong-blank combination produces faster acquisition and more resistance to extinction than does the right-blank condition. Results yielded by the right-wrong combination have been inconsistent. Several variables which interact with the type and combination of feedback children receive have not been systematically evaluated (e.g., incentive value, instructions, feedback accumulation, mode of delivery). Implications of laboratory research findings were then considered in relation to prototypic research designed to modify and improve children's academic learning. The general conclusion was that those concerned with applied research have overlooked some important findings, implications, and issues derived from laboratory research.During the past two decades, a number of investigators have demonstrated that conceptual learning is differentially affected by various types and combinations of