What is a Delphi process?

A Delphi process is a group facilitation technique, which is an iterative multistage process, designed to transform the opinion of individual experts into group consensus in situations where information is scant and a level of uncertainty exists, requiring expert judgement.

The classic Delphi process comprises multiple rounds, with questionnaires for each round being developed based on the input of the preceding round. This allows experts to review and adjust their opinion in light of the group response and, therefore, move towards a convergent viewpoint.

In a classic Delphi process, experts remain anonymous to each other, with question rounds being managed and analysed by a facilitator.

Classic Delphi processes have advantages over other group consensus techniques because experts are not brought together at the same time and in the same place, overcoming the practical difficulties of geography and diary clashes, while also removing some of the dynamics issues common in group meetings.

Various modifications of the Delphi process exist; one common modification replaces the third round of questions with a face-to-face expert meeting.

Factors important for the success of a Delphi process are the clear definition of the project objectives and measures of consensus, the selection of appropriate experts, a clear briefing and good starting material, and well-designed questionnaires that build on each other through effective analysis.

Delphi processes have been applied to a range of healthcare questions, as diverse as establishing best practice commissioning and estimating disease prevalence.