Effects of anonymity and evaluative tone on idea generation in computer mediated groups

A laboratory experiment was used to evaluate the effects of anonymity and evaluative tone on computer-mediated groups using a group decision support system to perform an idea-generation task. Evaluative tone was manipulated through a confederate group member who entered supportive or critical comments into the automated brainstorming system. Groups working anonymously and with a critical confederate produced the greatest number of original solutions and overall comments, yet average solution quality per item and average solution rarity were not different across conditions. Identified groups working with a supportive confederate were the most satisfied and had the highest levels of perceived effectiveness, but produced the fewest original solutions and overall comments.