Attentional contrast during sequential judgments:

of Dissertation Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy ATTENTIONAL CONTRAST DURING SEQUENTIAL JUDGMENTS: AN EXPLANATION FOR THE NUMBER-OF-LEVELS EFFECT By Els De Wilde August 2005 Chair: Chris Janiszewski Cochair: Alan D. J. Cooke Major Department: Marketing Normatively, the importance of an attribute does not depend on the number of levels on which it is defined, exterior levels being fixed. This dissertation examines a bias identified in the conjoint literature known as the number-of-levels effect, which occurs when consumers’ derived importance weights increase with the number of attribute levels. Borrowing from research on attention during category learning, this dissertation examines psychological mechanisms that underlie the number-of-levels effect. In contrast to earlier attentional accounts that have been offered for the bias, I propose that the weighting effect found in the number-of-levels studies is due to the attentional processes that are inherent to the sequential evaluation procedure. Analogously to attentional processes during category learning, consumers divide their attention between attribute dimensions and attribute levels when making sequential evaluations. Within a given trial, a mechanism of attentional contrast directs attention