An
exemplar is an instance of an event population that shares essential features with all other instances from the group of events that is defined by those features. In a sense, exemplars are case reports used to represent characteristics typical of a group of event. Commonly, exemplars are illustrative representations of information. An exemplar will provide a demonstration of an event. Exemplars used in conjunction with base-rates as case illustrations of event populations to enhance or detract from given base-rate information as the salient features of the exemplar are representative of the event population. As with news reports, exemplars are often added to provide a description of an event being discussed within a report and are chosen for their entertaining qualities.
Base-rates present descriptions limited to certain general features of the event population. Base-rate information often comes in the form of a numerical representation such as the frequency with which an event occurs. Typically it is thought of as quantitative information about population events or a general description of the number of things or people in the setting. They are overwhelmed by exemplars in many circumstances, it does not appear that they are always ignored. Prior investigations suggest that base-rates are perceived by decision makers as more reliable and can influence decisional confidence more than exemplars. Base-rates are perceived as more truthful, than exemplars. Nevertheless, recent research has shown that exemplification effects are prone to other perceptual phenomena. Some research suggests several disadvantages to the use of exemplars, particularly in relation to perceptual bias that might result from their use. Exemplars are also said to play a role in perpetuating negative stereotypes, and in isolation are frequently found to be inefficient sources of information. Exemplar information has largely been found to be less reliable than base-rate information. In part, because it is seldom collected or presented in a systematic manner. Exemplification research demonstrates that individuals often base their assessment of social reality more strongly on attributes of the exemplars selected for inclusion in media reports than statistical representations of information. This has been found problematic when the exemplar is atypical and chosen for its entertaining or sensational qualities, a common occurrence within news stories. ==References==