The present paper is intended to review the recent experimental studies of group problem solving. It does not deal with all aspects of group problem solving, "however. Our purpose is to consider several major variables which are known to affect group process and group productivity, and to examine them as they relate to group problem solving. These variables are group task, group size and group member attitude. Moreover, this paper will deal with the mathematical models in group problem solving as important as the generalizations from experimental data.