What is the Delphi cost estimating approach?

• A. Where expert opinion is collected, summarized and redistributed through several iterations
• B. A single expert estimate
• C. Random sampling of historical data
• D. Anecdotal estimates

Answer: (A)

The Delphi cost estimating approach is a structured, iterative way to harness expert judgment. In this method, specialists provide estimates independently and anonymously. A facilitator then collects these estimates, summarizes them (showing measures like the average and spread), and feeds that summary back to the group. In subsequent rounds, experts can revise their estimates after seeing how others judged the problem, and this process repeats until the estimates stabilize or a predefined stopping point is reached. The anonymity and controlled feedback help reduce bias, prevent one voice from dominating, and leverage diverse expertise to produce a more credible, consensus-based estimate. This approach is distinct from relying on a single expert, sampling historical data randomly, or using anecdotal opinions, all of which lack the iterative, synthesized consensus that the Delphi method provides.