Organizational Behavior and Human Decision Processes Vol. 82, No. 2, July, pp. 171–193, 2000 doi:10.1006/obhd.2000.2881, available online at http://www.idealibrary.com on Information Processing at Successive Stages of Decision Making: Need for Cognition and Inclusion–Exclusion Effects Irwin P. Levin University of Iowa Mary E. Huneke University of Washington, Bothell and J. D. Jasper University of Toronto Levin and Jasper’s (1995) phased narrowing technique for tracking changes in information usage across successive stages of the decision-making process was combined with Huneke’s (1996) “pull-down menu” extension of Payne, Bettman, and Johnson’s (1988) software package for generating measures of information processing. Because this technique provided considerable data for each individual subject at each stage, we were able to focus on individual differences in information processing across stages, most notably differences related to need for cognition (NC; Caci- oppo & Petty, 1982). In a computerized information search and decision task, 60 college students were first asked to narrow their options for purchasing a notebook computer to form a consider- ation set and were then asked to make a final choice from this set. At the consideration set formation stage, half the subjects were instructed to adopt a mindset to include options while the other half were asked to exclude options. Especially in the inclu- sion condition where subjects showed greater narrowing of The authors especially acknowledge the invaluable contribution of Alan C. Huneke, author of the ComputerShop software used in this research. The authors also thank the following students for their help in collecting and compiling data: Wendy Forbes, Tara Burmeister, Joel Temperley, and Vy Nguyen. Address correspondence and reprint requests to Irwin P. Levin, Department of Psychology, University of Iowa, 11 Seashore Hall, Iowa City, IA 52242-1407. 171 0749-5978/00 $35.00 Copyright  2000 by Academic Press All rights of reproduction in any form reserved.