Perceived Frequency of Recurrent Events
Abstract
A series of experiments involving over 650 individuals studied how people judge the frequency of various recurrent events. The judgements exhibited a highly consistent but systematically biased subjective scale of frequency. Two kinds of bias were identified: (a) a tendency to overestimate small frequencies and underestimate larger ones, and (b) a tendency to exaggerate the frequency of some specific events and to underestimate the frequency of others, at any given level of objective frequency. These biases were traced to a number of possible sources including disproportionate exposure, memorability or imaginability of various events. Subjects were unable to correct for these sources of bias when specifically instructed to avoid them. Comparisons with previous laboratory studies are discussed, along with methods for improving frequency judgements.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1977
- Accession Number
- ADA057271
Entities
People
- Barbara Combs
- Baruch Fischhoff
- Mark Layman
- Paul Slovic
- Sarah Lichtenstein