R. B. Gallupe, L. Bastianutti, and W. H. Cooper (1991) attributed the superiority of electronic brainstorming to a number of factors, including the technology's ability to reduce production blocking. In the present article, the authors manipulated production blocking in 3 experiments and assessed the performance of blocked and unblocked electronic brainstorming groups and verbal brainstroming groups. When normal electronic brainstorming groups were compared with verbal brainstroming groups, electronic brainstorming groups were found to be significantly more productive, which replicated earlier research results. In contrast, blocked electronic brainstorming groups performed at the same (or lower) levels as verbal brainstorming groups in all 3 experiments. The authors conclude that the reduction in production blocking inherent in using the electronic brainstorming technology is 1 reason that electronic brainstorming groups are more productive than verbal brainstorming groups.