This is a Lexicon entry: the mechanism, when it shows up, and the countermeasure. The full correction, with real-world cases and the audit prompt, hasn't been written yet.
Definition
Primary concept: Availability Heuristic. This entry examines a specific dimension; see Availability Heuristic for the broader mechanism.
When it shows up
News-driven risk assessment (shark attacks feel common). Decisions made after emotional exposure. Any judgment that relies on examples currently in mind. Modern context: A company's quarterly strategy review focuses heavily on the competitor who just launched a viral product - spending 40% of the meeting on a 3% market share player - while spending 10 minutes on the distribution partnership that drives 60% of revenue.
Failure mode
Attention-grabbing features dominate the judgment, not because they are diagnostic but because they are easy for the mind to hold. Loud, vivid, recent, unusual cases get weighted far above duller but more informative data.
Countermeasure
Before judging from salient cases, ask: 'What is the boring average and how does this compare?' Salient data is memorable because it is unusual. When correction costs more than the bias: When the salient feature is genuinely the most decision-relevant one. A physician noticing an unusual symptom, an investor noticing a management change, a parent noticing changed behaviour - salient information is often salient for good reason. The bias is correcting only when salience and relevance are demonstrably decoupled.
Related traps
Also connected in the map6 more, locked
Credit & first seen
DiscoveredSimpson, E.H. (1951).The interpretation of interaction in contingency tables.Journal of the Royal Statistical Society: Series B 13(2), 238-241 source ↗
Also revealed
Entry #47 of 631 in The Lexicon · see the full Lexicon