EXPLANATIONS OF INDIVIDUAL-GROUP PERFORMANCE DIFFERENCES - WHAT SORT OF BONUS CAN BE GAINED THROUGH GROUP-INTERACTION

The issues of whether or not groups outperform individuals on multiple -item problem-solving tasks and the size of the performance difference were discussed. The level of analysis was found to be an important co nsideration-groups outperformed their best member at the aggregate lev el of analysis (i.e., total score), but often failed to perform at the level of the best member on individual items. It was argued that grou ps outperform individuals al the aggregate level because group members often have complementary bases of knowledge that can compensate for e ach other's weaknesses and because of ''synergistic'' effects in group s. Implications for using groups as decision-making units in applied c ontexts were discussed.