AnM.22: Delphi


The Delphi method is a forecasting procedure based on structural surveys and captures the experience and knowledge of competent experts, who give estimates and predictions on certain complex and uncertain issues. It facilitates the transfer of implicit and tacit knowledge to more explicit knowledge and yields both qualitative and quantitative results.

The general aim of Delphi survey is to collect and synthesise opinions of a large group of experts and to achieve a degree of convergence with regard to the assessing and predicting long-term issues where i) future developments are highly uncertain; ii) there is no empirical database; iii) external factors are likely to have a determining effect. The specific objectives of a Delphi process are: i) to gather the information from a large group of participants necessary for dealing with a specific topic; ii) to make it understandable; iii) to elaborate grounded recommendations for various actions. The following four general types of Delphi processes are most applicable: i) Trend Delphi produces a forecast of a trend into the future along with the mental model of the group; ii) Problem Solving Delphi collects solutions to the problem which are rescaled to a group interval scale; iii) Policy Delphi seeks grounded policy resolutions; iv) Cross Impact Modeling, which is a collaborative building of a model of the future possible outcomes of a set of unique events.

Typically, the Delphi process consists in going through four stages: i) selection of the expert panel; ii) exploring the problem under consideration and exposing new insights and additional relevant material; iii) reaching a collective understanding of how the group views the issue;

iv) evaluating the differences and potential disagreements and reaching a consensus.

Data sources:

  • Successive expert panel meetings.
  • Workshop and interviews  
  • Multi-round or online questionnaires

The Delphi method:

  • ”may be characterized as a method for structuring a group communication process so that the process is effective in allowing a group of individuals, as a whole, to deal with a complex problem.
  • is a ”relatively strongly structured group communication process, in subjects, on which naturally unsure and incomplete knowledge is available, are judged upon by experts” (Häder and Häder, 1995)


  • Cuhls, K. (1998), Technikvorausschau in Japan, Heidelberg: Physica,Technik, Wirtschaft und Politik, 29.
  • Cuhls, K. (2005): Delphi surveys, Teaching material for UNIDO Foresight Seminars.
  • Dalkey, N. C. (1969): The Delphi Method: An Experimental Study of Group Opinion, prepared for United States Air Force Project Rand, Santa Monica .
  • Linstone, H. A. and Turoff, M. (eds., 1975), The Delphi Method - Techniques and Applications, Reading: Addison-Wesley.