Biases in future-oriented Delphi studies: A cognitive perspective

•Investigates effects of selected cognitive biases on future-oriented Delphi studies•Explains the mode of operation of each bias as well as underlying mechanisms•Suggests design features to mitigate cognitive biases•Design features include panel heterogeneity, warnings, and post-hoc procedures

Delphi is an established information gathering and forecasting approach that has proven to deliver valuable results in a wide variety of specialist fields. Yet, Delphi studies have also continuously been subject to critique and doubt, particularly concerning its judgmental and forecasting accuracy. To a large part this can be attributed to the substantial discretion researchers have in their design and implementation. Awkwardly designed Delphi studies may lead to severe cognitive biases that adversely affect the research results. This paper takes a cognitive perspective by investigating how different cognitive biases take effect within future-oriented Delphi studies and how their unfavorable impacts can be mitigated by thoroughly adapting specific Delphi design features. The analysis addresses cognitive biases affecting panelists' initial estimates — namely framing and anchoring as well as the desirability bias — as well as such cognitive biases taking effect during feedback and revision loops — namely the bandwagon effect and belief perseverance.