tel: + 33 (0)1 45 81 83 19 fax:+ 33 (0)1 45 65 95 15Abstract. This overview paper defends an augmented cognitively oriented generic-design hypothesis: there are both significant similarities between the design activities implemented in different situations and crucial differences between these and other cognitive activities; yet, characteristics of a design situation (related to the design process, the designers, and the artefact) introduce specificities in the corresponding cognitive activities and structures that are used, and in the resulting designs. We thus augment the classical generic-design hypothesis with that of different forms of designing. We review the data available in the cognitive design research literature and propose a series of candidates underlying such forms of design, outlining a number of directions requiring further elaboration. This paper is a first step in an endeavour to assert an augmented generic-design hypothesis (which concluded our book, The Cognitive Artifacts of Designing, Visser, 2006b): analysed from a cognitive viewpoint, design has specific characteristics that distinguish it from other cognitive activities, but also takes on different forms depending on the main dimensions of the design situation. Examination of this hypothesis, which is the object of this paper, may have consequences for both theory and practice in the domain of design. Support for the hypothesis may have consequences for design environments, assistance, and education. It may, for example, guide the development of modalities for supporting designers when they are involved in the construction of representations or in the management of constraints and criteria. Given the mostly dispersed and anecdotal discussion of the different components that make up the hypothesis, our aim here is to articulate them in an overview paper.Reviewing various empirical studies of activities "as diverse as software design, architectural design, naming and letter-writing," Carroll (1979/1984) stated that these different design activities "appear to have much in common" (p. 234). A number of authors have defended that, compared to other professionals, designers have specific forms of knowledge (e.g., Cross, 2001b;2002b ). Combining the positions underlying these two claims, Goel and Pirolli (1989; proposed the notion "generic design."Still other studies focus on the differences between design in different domains, examining a third aspect in this analysis concerning the nature of design (e.g., Akin, 2001;Purcell & Gero, 1996). In this paper we review and discuss these different aspects of design, focussing on the third one, whose discussion seems the least organised in the design literature. The position defended in this paper is the following: there are both (1) significant similarities between the design activities implemented in different situations and (2) significant differences between design and other cognitive activities; yet, (3) characteristics of a design situation (i.e., characteristics related to the design process,...
