Delphi technique

Last reviewed 09/2021

Delphi method

• Delphi technique is a widely used and accepted mehod for gathering data from respondents within their domain of expertise.
  • Delphi technique can be used for achieving the following objectives:
    • 1. to determine or develop a range of possible program alternatives;
    • 2. To explore or expose underlying assumptions or information leading to different judgments;
    • 3. To seek out information which may generate a consensus on the part of the respondent group;
    • 4. To correlate informed judgments on a topic spanning a wide range of disciplines, and;
    • 5. To educate the respondent group as to the diverse and interrelated aspects of the topic
      
      
  • Delphi technique is well suited as a method for consensus-building by using a series of questionnaires delivered using multiple iterations to collect data from a panel of selected subjects
    
  • subject selection, time frames for conducting and completing a study, the possibility of low response rates, and unintentionally guiding feedback from the respondent group are areas which should be considered when designing and implementing a Delphi study
    • experts answer questionnaires in two or more rounds
      • after each round, a facilitator provides an anonymous summary of the experts' forecasts from the previous round as well as the reasons they provided for their judgments
      • thus, experts are encouraged to revise their earlier answers in light of the replies of other members of their panel
      • believed that during this process the range of the answers will decrease and the group will converge towards the "correct" answer. Finally, the process is stopped after a pre-defined stop criterion (e.g. number of rounds, achievement of consensus, stability of results) and the mean or median scores of the final rounds determine the results

Reference:

• Norman Dalkey, Olaf Helmer (1963). An Experimental Application of the Delphi Method to the use of experts. Management Science, 9(3), Apr 1963, pp 458-467.