Group composition and performance: four studies of the relationships amongst member ability, group process, decision schemes and effectiveness

Abstract

Studies of small group performance have long been dominated by the view that interaction processes amongst team members are the critical determinants of task achievement. Yet few studies show that training in group dynamics leads to performance improvements (Kaplan, 1979). The emphasis on group level processes has overshadowed the influence of member task ability on group performance. The research presented here aims to redress this imbalance.

Four integrated studies are undertaken employing different research methodologies. Study 1 explores the group performance/size relationship, and the moderating effects of member expertise and social decision schemes. Both simulated and interacting groups are investigated. Performance is found to be a positive linear function of log size. The slope of this graph is steeper for high ability members and more rational decision strategies.

Study 2 explores the types of decision strategies used by interacting groups. Team performance is separated into assembly and information processing components. The former is a function of average member ability. The latter is determined by the degree of fit with a rational non-unit weight decision scheme. Study 3 shows for a group to achieve this strategy, member participation rates must be allocated in proportion to task expertise. Study 3 also demonstrates differences between perceived and actual influence: the former is principally determined by participation level, the latter by expertise.

Study 4 builds on the findings of the first three - that group performance is a function of member task expertise and strategies for its use. It shows that task training for individuals enhances member ability, group process and decision schemes and performance. All studies employ the same task: the NASA moon exercise. A total of 400 subjects working individually and/or in 70 interacting groups are involved in the studies.