Eliminating the Low Prevalence Effect in Visual Search with a Remarkably Simple Strategy

The low prevalence effect in visual search occurs when rare targets are missed at a disproportionately high rate. This effect has enormous significance in health and public safety and has proven resistant to intervention. In three experiments (Ns = 41, 40, 44), we document a dramatic reduction of the effect using a simple cognitive strategy requiring no training. Instead of asking participants to search for the presence or absence of a target, as is typically done in visual search tasks, we asked participants to engage in “similarity search” – to identify the display element most similar to a target on every trial, regardless of whether a target is present. Under normal search instructions, we observed strong low prevalence effects. Using similarity search, we failed to detect the low prevalence effect under identical visual conditions across three experiments.