This report describes the results of three studies which investigated the use of PLATO to teach problem solving. Subjects were 244 children from kindergarten through third grade. The first study explored the extent to which kindergartners and second graders used the knowledge about which answers were right and which were wrong to develop the correct strategy to solve a novel picture problem. The next study looked at the procedures used by kindergartners and second graders while they were in the process of trying to get the answer. The third study considered three conditions of teaching first and third graders the necessary problem solving skills: experience only, feedback consisting of a visual record of the student's work on the first five problems, and interactive instructional feedback on how to solve each problem that the child had done wrong. Abstracts, methods, results, and discussions are given for each of the studies. Results of this research led to a post hoc study which is described. Seven figures show sample displays and nine references are also given.