"What I'm going to suggest is a road map of factors in failures of group decision making. I'll divide the answers into a sequence of four somewhat fuzzily delineated categories. First of all, a group may fail to anticipate a problem before the problem actually arrives. Secondly, when the problem arrives, the group may fail to perceive the problem. Then, after they perceive the problem, they may fail even to try to solve the problem. Finally, they may try to solve it but may fail in their attempts to do so. While all this talking about reasons for failure and collapses of society may seem pessimistic, the flip side is optimistic: namely, successful decision-making. Perhaps if we understand the reasons why groups make bad decisions, we can use that knowledge as a check list to help groups make good decisions."