Delphi Method for Strategy Foresight

Face-to-face groups suffer from dominance by forceful or senior members, bandwagon and conformity effects, and reluctance to reverse a publicly stated position. Rowe and Wright identify Delphi's defining features - anonymity, iteration, controlled statistical feedback, and aggregation of the final round - as precisely the mechanisms that remove these distortions. Experts respond independently and revise in light of arguments and the group summary rather than social pressure, which empirically tends to improve judgment over unstructured group discussion.

Linstone and Turoff and later reviewers find that most of the convergence happens within two to four rounds; additional rounds add little and risk panelist fatigue, so iteration should stop when responses stabilize rather than at a fixed count. Panel size is chosen for expertise and diversity rather than statistical power - panels often range from roughly ten to a few dozen qualified experts. The decisive factor is the quality and relevance of the experts, not the raw number.

Not necessarily. The conventional Delphi seeks reasoned convergence, but Rowe and Wright caution that the proper stopping criterion is stability of responses, not forced unanimity. The policy-Delphi variant deliberately aims to surface and structure the full range of options and arguments rather than to agree on one answer. Treating consensus as the objective risks manufacturing false agreement and discarding well-argued dissent, which for strategic foresight is often the most valuable output.