Availability heuristic
Ευρετικός κανόνας της διαθεσιμότητας
Judging how common or how likely something is by how easily examples come to mind. Vivid, recent and repeated things come to mind easily, and that ease gets read as support. It describes ordinary judgement in everybody, so the honest use of it is on your own estimates rather than on somebody else.
How to spot it
When an example arrives fast, ask why it arrived fast. Because that kind of thing is common, or because you happened to hear this one three times this week?
The research behind the term
The term is not our invention. It comes from published research, and what follows is what that research found — our own synthesis of the published abstract, not a translation of the original.
Tversky, A., & Kahneman, D. (1974). Judgment under Uncertainty: Heuristics and Biases — doi:10.1126/science.185.4157.1124
What it found
- Three heuristics we use when judging under uncertainty are described: representativeness, availability, and adjustment from an anchor.
- Representativeness is engaged when we judge the probability that an object or event belongs to a category.
- Availability is engaged when we estimate the frequency of a category or the plausibility of a development, on the basis of how easily instances come to mind.
- These heuristics are highly economical and usually effective, but they lead to systematic and predictable errors.
How it found it
A theoretical article synthesizing the authors' experimental findings on judgment under uncertainty into three general mechanisms with predictable deviations.
What it means for critical thinking
That something comes easily to mind does not mean it is frequent — this one distinction invalidates a large part of our everyday reasoning.
Practised in
The term does not stay a definition. It appears inside missions where the pattern happens in real time and you have to recognise it as it happens to you.
The Viral Claim
Sources
Every claim on this page maps to published research. The citations link to the original source.
- Tversky, A., & Kahneman, D. (1974). Judgment under Uncertainty: Heuristics and Biases — doi:10.1126/science.185.4157.1124