Table 1
Illustrative medical examples of selected heuristics
Heuristics | Examples |
Availability: Estimating the likelihood of an event (X) by the ease with which instances of X come to mind, i.e., how available they are. | Recent experiences caring for patients with bacteremia were associated with doctors' higher estimated probabilities that hospital inpatients (for whom blood cultures had been taken) had bacteremia [16]. |
Representativeness: Where estimating the likelihood of an event (X) is mediated by the degree to which it represents the class to which X belongs. | Drives the diagnostician toward looking for prototypical manifestations of disease: "If it looks like a duck, walks like a duck, quacks like a duck, then it is a duck." Yet restraining decision-making along these pattern-recognition lines leads to atypical variants being missed [17]. It inappropriately ignores, for example, prior probabilities [18]. |
Affect: Where an initial affective reaction biases the resultant decision. | When toxicologists were asked to assess the risk associated with a very small exposure to 30 chemical items, degree of risk was mediated by their assessment of how 'bad-good' each chemical was [19]. |