According to the PMBOK® Guide, the Delphi technique is a specialized information-gathering and group decision-making technique used to reach a consensus among a panel of independent experts.
Expert Judgment: The defining characteristic of the Delphi technique is the reliance on individuals with specific expertise. These experts provide their input anonymously to avoid the " bandwagon effect " or " groupthink, " where individuals might be influenced by more dominant personalities in a face-to-face meeting.
Iterative Process: A facilitator uses a questionnaire to solicit ideas or forecasts from the experts. The responses are summarized and then recirculated to the experts for further comment. This process is repeated through several rounds until a consensus—the " best option " —is reached.
Anonymity and Independence: Unlike a standard workshop, the participants often do not know who the other experts are. This ensures that the final decision is based purely on the technical or professional merit of the arguments rather than social pressure.
Analysis of other options:
Option B: This describes a simple screening or elimination process based on cost constraints. While cost is a factor in many decisions, it is not the defining procedural characteristic of the Delphi method.
Option C: This describes a Multicriteria Decision Analysis or a weighted scoring model. The Delphi technique relies on expert consensus and subjective professional judgment rather than a purely automated or predefined algorithm.
Option D: This describes the Nominal Group Technique (NGT). NGT involves brainstorming (listing), followed by ranking and voting. While similar to Delphi in that it seeks consensus, NGT is typically done in person and involves a voting tally rather than anonymous iterative rounds of expert feedback.
Per PMI standards, the Delphi technique is a powerful tool for reducing bias in data collection and ensuring that project estimates or strategic decisions are grounded in the collective expertise of a specialized group.
