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 brainstorming groups. When normal electronic brainstorming groups were compared with verbal brainstorming 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