Origins
Developed at the RAND Corporation in the 1950s by Norman Dalkey and Olaf Helmer for technology forecasting and published in 1963. The name refers to the oracle of Delphi.
Four features
- Anonymity reduces the influence of dominant individuals.
- Iteration: usually two to four rounds.
- Controlled feedback: the facilitator summarises earlier results.
- Statistical group response: medians and interquartile ranges show the degree of consensus.
Procedure
Define the problem and select a panel; run an open first round; turn responses into a rating questionnaire; share results and minority reasoning in a third round; judge consensus and report.
Policy Delphi
Turoff's policy Delphi aims to surface opposing views and their arguments rather than force consensus, and may include stakeholders. It is often paired with brainstorming when exploring policy options; unlike deliberative polling, its participants are experts.
Strengths and limitations
It collects dispersed expertise without meetings and limits groupthink, but results depend on panel selection, attrition rises with each round, and consensus is not the same as accuracy.
References
- Dalkey, N., & Helmer, O. (1963). An experimental application of the Delphi method to the use of experts. Management Science, 9(3), 458-467.
- Linstone, H. A., & Turoff, M. (Eds.). (1975). The Delphi Method: Techniques and Applications. Addison-Wesley.
- Hsu, C.-C., & Sandford, B. A. (2007). The Delphi technique: Making sense of consensus. Practical Assessment, Research, and Evaluation, 12(10).