Date of Degree
PhD (Doctor of Philosophy)
Paul D. Windschitl
Numeric estimates are influenced by a variety of factors including a person's knowledge and the presence of numeric anchors. In general, greater knowledge leads to more accurate estimates and the presence of anchors decreases accuracy. This dissertation is focused on the relationship between these two factors. At an intuitive level, it seems that increased knowledge should lead to a decrease in anchoring effects. Unfortunately, the research on knowledge and anchoring is quite mixed. This dissertation describes four studies--the first three were experimental and the last was correlational--that addressed two primary questions: 1) Does knowledge level moderate anchoring effects such that greater knowledge in a domain is associated with smaller anchoring effects? 2) Does this relationship depend on the type of knowledge one has? Studies 1 and 2 provided an answer to the first question. In Study 1, participants who studied a list of country populations--i.e., high knowledge participants--were less influenced by anchors than participants who learned irrelevant information. In Study 2, those participants who studied a list of new car prices were less influenced by anchors than participants who learned irrelevant information. In Study 3, participants learned information designed to influence different types of knowledge. The results of Study 3 supported the prediction that only those participants in conditions that increased metric knowledge--and not mapping knowledge--would exhibit reduced anchoring effects. Finally, in Study 4, participants' knowledge was measured and compared to their anchoring effects. Contrary to expectations, none of the knowledge measures were related to the participants' anchoring effects. Theoretical and practical implications, as well as reasons why the last study was not consistent with the first three, are discussed. Taken together, these studies indicate that both the amount and type of knowledge one has are important in determining one's susceptibility to anchoring effects.
Copyright 2011 Andrew Robert Smith