Judgment and Decision Making

3

HINDSIGHT ≠ FORESIGHT

The effect of outcome knowledge on judgment under uncertainty

Baruch Fischhoff

HEBREW UNIVERSITY OF JERUSALEM, ISRAEL

Abstract

One major difference between historical and nonhistorical judgment is that the historical judge typically knows how things turned out. In Experiment 1, receipt of such outcome knowledge was found to increase the postdicted likelihood of reported events and change the perceived relevance of eventdescriptive data, regardless of the likelihood of the outcome and the truth of the report. Judges were, however, largely unaware of the effect that outcome knowledge had on their perceptions. As a result, they overestimated what they would have known without outcome knowledge (Experiment 2), as well as what ...