Prevalence Effect

(Statistical Ratio)


Statistical Ratio
Link to Dbpedia

What is Prevalence effect?

In psychology, the prevalence effect is the phenomenon that one is more likely to miss (or fail to detect) a target with a low prevalence (or frequency) than a target with a high prevalence or frequency. A real-world application of this phenomenon occurs in airport security screening; since a very small proportion of those going through security checkpoints carry weapons, security staff may fail to detect those attempting to carry weapons onto a plane. In visual perception, target prevalence describes the salience (or visibility) of an object or objects in the environment and influences visual search.An experiment similar to an x-ray baggage search at an airport reveals how likely one is to make errors when searching for low-prevalence targets. A 50-percent prevalence produced a seven-percent error rate, typical for laboratory search tasks of this sort; a 10-percent prevalence produced a 16-percent error rate, and prevalence under one percent produced a 30-percent error rate. Humans normally search for common things, such as a favorite jelly-bean flavor in a collection of flavors. When they look for rare things (such as a jelly bean in a bag of lollipops), they are likely to abandon the search quickly because the probability of success and the stakes are low. Some searches combine low prevalence with high stakes; medical screenings such as mammography or cytopathology, is an important search for a target rarely present (typically under one percent). Missing a rare target, such as a weapon smuggled onto an airplane, may have serious consequences.

Technology Types

psychological effectstatistical ratiovisual perception


The prevalence effect

Tech Info

Source: [object Object]
 — Date merged: 11/6/2021, 1:32:57 PM
 — Date scraped: 5/20/2021, 6:06:02 PM