Final answer:
The availability heuristic is a cognitive process where people make decisions based on how easily information can be recalled, which can lead to skewed perceptions of frequency or probability.
Step-by-step explanation:
The cognitive rule that judges the likelihood of things in terms of their availability in memory is called the availability heuristic. This is a mental shortcut that helps individuals make decisions based on how easily information comes to mind.
The availability heuristic can lead to a biased way of thinking, as people tend to give undue weight to recent or vivid experiences. For example, individuals may overestimate the frequency of events that they recall quickly, such as airplane crashes or shark attacks, simply because they are dramatic and widely reported, despite being statistically rare events. The heuristic operates under the assumption that if something can be recalled easily, it must be important. However, this can cause misjudgments, because easy recall does not always correlate with actual frequency or probability.