Articulation of web site design constraints: Effects of the task and designers’ expertise Aline Chevalier a, * , Nathalie Bonnardel b a University of Paris X-Nanterre, Cognitive Processes and Interactive Conducts Laboratory, Department of Cognitive Psychology (Ba ˆt. C), 200 Avenue de la Re ´publique, 92001 Nanterre Cedex, France b University of Provence – Aix-Marseille I, Research Center in Psychology of Cognition, Language and Emotion (PsyCLE), Department of Cognitive and Experimental Psychology, 29 Avenue Robert Schuman, 13621 Aix-en-Provence Cedex 1, France Available online 22 June 2006 Abstract This paper aims at contributing to a better understanding of the cognitive activities of web site designers and, more precisely, their articulation and satisfaction of various design constraints. In this paper, we first present an experiment in which professional and novice designers have to evaluate a web site developed for reflecting usability errors identified in web sites. Then, the results obtained in this evaluation task are compared with results previously obtained in a design task, in which profes- sional and novice designers had to create a web site. Data analyses focused on the number and nat- ure of constraints articulated by designers in these two types of tasks (evaluation vs design). In particular, we distinguished constraints linked with the client of the site and constraints linked with the future web users. The obtained results show effects of both the level of expertise and the task. While designing, all of the designers focused mainly on constraints linked with the client. In contrast, while evaluating the web site, novices focused on constraints linked with the user, whereas profes- sionals shared their attention between these two kinds of constraints (client vs user-oriented con- straints). Based on these results, we conclude with ways for supporting designers’ activities. Ó 2006 Elsevier Ltd. All rights reserved. Keywords: Web sites; Designers; Expertise; Constraints 0747-5632/$ - see front matter Ó 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.chb.2006.04.001 * Corresponding author. Tel.: +33 1 40 97 75 28; fax: +33 1 40 97 71 58. E-mail address: Aline.Chevalier@u-paris10.fr (A. Chevalier). Computers in Human Behavior 23 (2007) 2455–2472 www.elsevier.com/locate/comphumbeh Computers in Human Behavior