Piagetian tasks varying in complexity were administered to elementary school children in grades K-3. Differences between the attainment of similar concepts occurred when the tasks required different types of inference patterns, had different goals, or involved different percepts. Discusses curriculum implications. (AL)

Analyzes the performance of the Electronic Task (ET), to test for combinatorial reasoning, over a broad range of subject ages and abilities in order to evaluate it as a substitute for the original Chemical Task (CT). (GA)