AVAILABILITY HEURISTIC IN JUDGMENTS OF SET SIZE AND FREQUENCY OF OCCURRENCE

The availability heuristic has been widely cited as an important facto r in the judgment process. However, the evidence that availability is important in judging category size is not fully convincing. Moreover, several reports suggest that availability may not be a factor in judgi ng frequency of occurrence. Path analysis was used in 3 experiments de signed to assess the role of memorial availability in judgments of cat egory size and frequency of occurrence. In judging set size, there was consistent support for the availability heuristic; that is, set size judgments were reliably influenced by the contents of memory. By contr ast, in accordance with earlier results, availability was not a signif icant factor when Ss judged frequency of occurrence.