The tendency to judge the frequency or probability of an even in terms of how easy it is to think of examples of that event.
The tendency to estimate the likelihood that an event will occur by how easily instances of it come to mind.
A rule of thumb often used to make probability estimates, which depends on the frequency with which certain events readily come to mind. This can lead to errors, since, for example, very vivid events will be remembered out of proportion to their actual frequency of occurrence.
Basing judgments on events that are easier to recall.
The availability heuristic is a rule of thumb, heuristic, or cognitive bias, where people base their prediction of an outcome on the vividness and emotional impact rather than on actual probability.