Effects of anticipated evaluation on individual brainstorming performance.

Experimental investigations of the relative effectiveness of group versus individual brainstorming procedures have consistently reported the finding of individual brainstorming superiority. Several hypotheses concerning the nature of the inhibitory factor or factors operating in the group situation have been postulated. One which has been mentioned frequently involves postulation of the presence of anticipated evaluation in brainstorming groups. That is, it has been hypothesized that group members may believe that other members will evaluate critically ideas which they produce. As a result, freewheeling production of ideas may be suppressed in the group context. The present study manipulated different conditions of anticipated evaluation for subjects who brainstormed alone. Performance in these conditions was compared to performance in two control conditions, one of individual brainstorming and one of group brainstorming (N = 4), both of which were conducted in the absence of experimentally imposed evaluation. Within the evaluation conditions, two aspects of evaluation were manipulated via instructions presented to subjects prior to brainstorming. Subjects were told either that evaluation would occur immediately upon their production of ideas or that it would occur at a later date via evaluation of their taped responses. In addition, subjects were informed either that evaluation would be of a relevant nature, and would assess the quality of their ideas, or that it would be irrelevant, concerned with evaluating some aspect of their speech patterns for linguistic analysis. A problems factor was also manipulated. Subjects in evaluation conditions as well as those in group and individual non-evaluation conditions were given one of two problems to brainstorm. Results indicated that individual brainstorming was superior to group brainstorming, in terms of the number of nonoverlapping ideas produced per four individuals, regardless of the presence or absence of anticipated evaluation. There were no differences in performance across the four evaluation conditions, nor were there differences between individual brainstorming under conditions of evaluation and that in the absence of evaluation. Productivity in both individual conditions, however, significantly exceeded the productivity of group brainstorming. Thus, anticipated evaluation, as manipulated in the present study, did not have an inhibitory effect on brainstorming. As such, a hypothesis of anticipated evaluation as the major inhibitory factor operating in group brainstorming did not receive support. Results also showed a significant effect of problem. Subjects brainstorming the irrelevant "Thumbs" problem produced a greater number of ideas than did those brainstorming the more realistic "Energy" problem.