Delphi Technique
A disciplined approach to prediction and estimation that iteratively gathers input from experts until their views align into a consensus.
Key Points
- Uses multiple anonymous rounds of expert input to reduce bias and groupthink.
- A neutral facilitator summarizes results and shares feedback between rounds.
- Converges toward consensus; stop when variance is low or a set number of rounds is reached.
- Helpful for estimating cost, schedule, scope, and risk when data is limited or uncertain.
Example
A project manager needs effort estimates for a new analytics feature. She sends a questionnaire to several SMEs, collects their estimates, and shares an anonymous summary of ranges and rationales. After two more rounds of revision based on the feedback, the experts converge on a realistic effort range the team can use for planning.
PMP Example Question
A project involves unfamiliar technology, and the PM wants unbiased duration estimates without one expert dominating the discussion. Which technique should be used?
- Delphi technique
- Brainstorming session
- Monte Carlo simulation
- One-on-one expert judgment interview
Correct Answer: A — Delphi technique using anonymous expert consensus
Explanation: The Delphi technique gathers estimates from experts anonymously over multiple rounds to reduce bias and reach a consensus, unlike brainstorming, interviews, or simulation.
