解釋：

A formal method used to generate expert collective decisions. The steps in the process are made explicit and could be replicated. In the Delphi method, participants receive questionnaires and record their views. The responses are aggregated by the organizers and sent back to participants in summary form, indicating the group judgment and the individual's initial judgment. The participants are given the opportunity to revise their judgments, and the process may be repeated. In this method, the participants never meet face-to-face or interact directly.