Delphi: A reevaluation of research and theory

https://doi.org/10.1016/0040-1625(91)90039-IGet rights and content

Abstract

This paper examines critically the Delphi technique to determine whether it succeeds in alleviating the “process loss” typical of interacting groups. After briefly reviewing the technique, we consider problems with Delphi from two perspectives. First, we examine methodological and technical difficulties and the problems these have brought about in experimental applications. We suggest that important differences exist between the typical laboratory Delphi and the original concept of Delphi. These differences, reflecting a lack of control of important group characteristics/factors (such as the relative level of panelist expertise), make comparisons between Delphi studies unrealistic, as are generalizations from laboratory studies to the ideal of Delphi. This conclusion diminishes the power of those former Delphi critiques that have largely dismissed the procedure because of the variability of laboratory study results. Second, having noted the limited usefulness of the majority of studies for answering questions on the effectiveness of Delphi, we look at the technique from a theoritical/ mechanical perspective. That is, by drawing upon ideas/findings from other areas of research, we attempt to discern whether the structure of the Delphi procedure itself might reasonably be expected to function as intended. We conclude that inadequacies in the nature of feedback typically supplied in applications of Delphi tend to ensure that any small gains in the resolution of “process loss” are offset by the removal of any opportunity for group “process gain”. Some solutions to this dilemma are advocated; they are based on an analysis of the process of judgment change within groups and a consideration of factors that increase the validity of statistical/ nominal groups over their constituent individual components.

References (53)

  • N.C. Dalkey et al.

    The Delphi Method III: Use of Self-Ratings to Improve Group Estimates

    Technological Forecasting

    (1970)
  • A.D. Bender et al.

    Delphi Study Examines Developments in Medicine

    Futures

    (1969)
  • J.R. Salancik et al.

    The Construction of Delphi Event Statements

    Technological Forecasting and Social Change

    (1971)
  • R.M. Hogarth

    A Note on Aggregating Opinions

    Organizational Behavior and Human Performance

    (1978)
  • R.H. Ashton

    Combining the Judgments of Experts: How Many and Which Ones?

    Organizational Behavior and Human Decision Processes

    (1986)
  • D.G. Myers

    Polarizing Effects of Social Comparisons

    Journal of Experimental Social Psychology

    (1978)
  • G.W. Hill

    Group versus Individual Performance: Are N + 1 Heads Better than One?

    Psychological Bulletin

    (1982)
  • A. Lock

    Integrating Group Judgments in Subjective Forecasts

  • W.R. Ferrell

    Combining Individual Judgments

  • B.E. Flores et al.

    Subjective vs Objective Combining of Forecasts: An Experiment

    Journal of Forecasting

    (1989)
  • R. Nisbett et al.

    Human Inference: Strategies and Shortcomings of Social Judgement

    (1980)
  • I. Lorge et al.

    A Survey of Studies Contrasting the Quality of Group Performance and Individual Performance

    Psychological Bulletin

    (1958)
  • W.L. Uecker

    The Quality of Group Performance in Simplified Information Evaluation

    Journal of Accounting Research

    (1982)
  • R. Hastie

    Experimental Evidence on Group Accuracy

  • I.D. Steiner

    Group Process and Productivity

    (1972)
  • L.R. Hoffman

    Group Problem Solving

  • Cited by (494)

    • Mode choice support through an integrated Delphi-fuzzy logic model

      2024, Research in Transportation Business and Management
    View all citing articles on Scopus
    View full text