title: People focus on optimistic scenarios and disregard pessimistic scenarios while predicting task completion times.
abstract: Task completion plans normally resemble best-case scenarios and yield overly optimistic predictions of completion times. The authors induced participants to generate more pessimistic scenarios and examined completion predictions. Participants described a pessimistic scenario of task completion either alone or with an optimistic scenario. Pessimistic scenarios did not affect predictions or accuracy and were consistently rated less plausible than optimistic scenarios (Experiments 1-3). Experiment 4 independently manipulated scenario plausibility and optimism. Plausibility moderated the impact of optimistic, but not pessimistic, scenarios. Experiment 5 supported a motivational explanation of the tendency to disregard pessimistic scenarios regardless of their plausibility. People took pessimistic scenarios into account when predicting someone else's completion times. The authors conclude that pessimistic-scenario generation may not be an effective debiasing technique for personal predictions.
authors.affiliation: Department of Psychology, University of Waterloo, Ontario, Canada. newby@uwindsor.ca
authors.forename: I R
authors.initials: IR
authors.lastname: Newby-Clark
authors.forename: M
authors.initials: M
authors.lastname: Ross
authors.forename: R
authors.initials: R
authors.lastname: Buehler
authors.forename: D J
authors.initials: DJ
authors.lastname: Koehler
authors.forename: D
authors.initials: D
authors.lastname: Griffin
mesh_terms: D000339:Affect; D001290:Attitude; D005260:Female; D005544:Forecasting; D006801:Humans; D008297:Male; D011795:Surveys and Questionnaires