Influence of the amount and relevance of information on the speed and confidence of the response.

Abstract

Confidence in a belief is a feeling about the probability of the correctness of the belief. Research has shown that subjects tend to be overconfident in the correctness of their beliefs when that confidence is measured against the actual probability of the belief being correct. Further research has indicated the importance of the amount, relevance, and source of background information on the degree of confidence expressed in a belief. Phillips and Wright (1977) have proposed a three stage model for how confidence in a belief is evaluated and transformed into a confidence response. This research examined how the amount and relevance of information pertaining to a belief influenced the subject's confidence in the belief, and the plausibility of the Phillips and Wright confidence response model. Subjects were presented information about a hypothetical individual and were asked to indicate true or false that the profiled individual was from a particular occupation group, and their confidence in their true/false response. Profile information varied from high to low relevance for the occupation decision, and in the amount of information presented. Subject response times were measured, once the profile had been read and removed, from the presentation of the occupation statement to the subjects true/false response. Subjects indicated greatest confidence when the maximum amount of highly relevant information was presented. Further, information relevance alone produced a significant change in confidence, while the amount of information did not. The prediction of the Phillips and Wright model of greatest response times with subject expressions of moderate confidence was not supported. Instead, subjects responded most quickly when most confident and slowest when least confident. Information relevance was negatively related to response time while the amount of information was positively related to response time.