A mental shortcut that relies on immediate examples that come to a given person's mind when evaluating a specific topic, concept, method, or decision. This can lead to overestimating the likelihood of events occurring, simply because they are more memorable.
Definition: The tendency to make judgements by the ease with which ideas come to mind.
Example: Teachers improving course feedback ratings by asking students to name ten ways the course could be improved instead of two. Since it is more difficult to come up with ten ways from the mind, students rated the course more favourably.
Insight: If something is easily retrieved from memory, it will be judged to be more prevalent or large.
Insight: We often substitute facts with impressions about how easily something comes to mind.
Reference: Amos Tversky and Daniel Kahneman defined the concept. In was born out of the thought about what people actually do when they estimate the frequency of something.
Reference: Paul Solvic, Sarah Lichtenstein, et al: people's judgements about the frequency of death from various causes is biased by the media, which focuses on drama, novelty, or location.
Definition: The ease with which instances come to mind.
Insight: The availability heuristic helps explain why some public issues remain high on the public agenda, while others are neglected. People tend to weigh the relative importance of a subject by how easily it can be retrieved from memory, with the media playing a large role in this.
Insight: The availability heuristic means that when making judgements we substitute the objective facts with a subjective impression base on the ease with which instances come to mind.
Insight: The unexplained unavailability heuristic is closely related - we can make poor judgements or assumptions just because we cannot think of examples.
Insight: People's intuition is often the result of the availability heuristic.
Insight: Judgement of risk is often based on the availability heuristic: the risk of shark attacks is lower than many people perceive.
Insight: The availability heuristic can result in people focusing on the short term over the long term, especially when it comes to risk.
Insight: Probability estimates are highly skewed by the availability heuristic.
Definition: People estimate the probability of an event or frequency of something by the ease with which instances come to mind.
Insight: When people remember things not because of their actual frequency, but because it is vivid, gory, distinctive, or emotional - they will overestimate how likely it is.
Insight: The news can make people miscalibrated.
Reference: Amos Tversky and Daniel Kahneman defined the availability heuristic.
Example: Most people believe homicides are more prevalent than suicide because they are more heavily reported in the media.
Insight: People assess the likelihood of risk, by questioning how readily examples come to their mind.
Insight: The availability heuristic explains risk-related behaviour, including whether people buy insurance.
Definition: The ease of bringing to mind instances and the effect on our judgement of frequency.
Insight: Easy to recall and vivid events have a disproportionate impact on our judgement. We overemphasise examples or events that come easiest to our mind.
Definition: Related to how easily things come to mind.
Insight: We estimate the frequency of events according to the ease with which examples of the event can be recalled.
Definition: When we substitute a judgement of how easily examples come to mind for an assessment of frequency.
Insight: Theoretically, judgements of risk should be based on long term averages. In reality, recent incidents are given more weight because they come to mind more easily.
Definition: When the salient is mistaken for the statistical.
Insight: The conspicuous and emotional effect of events make us think they are occurring more frequently than in reality.
Insight: Errors in judgement come when people are presented with situations in which evidence needed to make a judgement is hard for them to retrieve from memory, or misleading evidence comes easily to mind.
Reference: Tversky and Kahneman: "the use of the availability heuristic leads to bias". Human judgement is distorted by what is memorable.
Insight: People predict the likelihood of an event based on how easily they can come up with an example.
Insight: People assess probability by asking whether a relevant event comes to mind.
Key Insights & Principles
Decision Making
We often base decisions on how readily information or examples come to mind.
Our judgement of probability and risk is often based on the availability heuristic.
Media impacts our decision making.
Judge risk and probability on long term averages, not easy to recall, recent examples.
Research and gather relevant information and examples.
