Effet du niveau d'expertise des concepteurs sur la prise en compte de contraintes et sur la qualité ergonomique de maquettes de sites web

Abstract

A great deal of research today examines the cognitive difficulties encountered by web site users, as well as the development of ergonomic guidelines for designers and the development of automatic evaluation tools. However, few studies focus on designers' cognitive functioning during the design of web sites. We argue that establishing the difficulties encountered by web site designers is a necessary first step to supporting their activity, especially when it comes to making web sites easier to use. More precisely, in this article, we argue that the designers' level of expertise and the presence or absence of client-prescribed design constraints influence : - The number and the nature of constraints articulated by designers. - The ergonomic quality of the web site sketches created by designers (that is to say the number of ergonomic problems identified in their sketches). To this end, we conducted an experimental study involving fourteen professional and novice designers. These designers had to produce a first sketch of a car dealer's web site in two conditions : - A condition with eleven client-prescribed constraints. - A condition without constraints. The results of the study showed that professional designers articulated more client constraints than novices. There were, however, no significant differences between professionals relating to the number of articulated client constraints, regardless of the experimental condition. Nevertheless, professionals did articulate more user constraints than novices. In particular, when novice designers have to consider client-prescribed constraints, they tend to focus on these constraints and experience difficulties adding user constraints or anticipating users' activities. An analysis of designers' sketches shows that all the designers experienced difficulties in implementing ergonomic constraints in the designs that they articulated. Based on the results of our study, we suggest three ways to better support web designers during the design process. The first two suggestions address the question how to help the designers to consider constraints. These constraints must be relevant to both the client's and the user's expectations in a balanced way throughout the design process. Tools to support designers should adapt to the designers' level of expertise. We also suggest a method for supporting professional and novice designers in considering and applying constraints that are relevant to site users and meet specific ergonomic constraints. In this way, we are able to propose a specific training program (during the designers' university or high school education) for helping designers to consider and to apply ergonomic recommendations in the web sites they develop. The paper concludes with a presentation of different studies conducted with professional and novice designers to help them in design web sites easier to use.