From computer to instrument system: a developmental perspective

Studies working within an activity theory frame have opened different paths in the HCI field. One of the fundamental points of these approaches focussed on activity is consideration of the constructive dimensions of the user's activity. Several authors have identified the complex relations between usage and design (Winograd and Flores, 1986; Suchman and Trigg, 1991) beyond this, that design continues in usage (Rabardel, 1995, 2002; Henderson and Kyng, 1991; Vicente, 1999).The approach that we put forward contributes to the development of this question: the continuation of design in usage. Based on an empirical situation (managing the maintenance of a broadcasting network for radio, television and telecommunications), we define the mediated activity. We look at the mediator and suggest conceptualizing it as a mixed functional entity: the instrument. We examine the emergence and development modalities of instruments during processes of instrumental genesis. We also show that instruments are components in more general systems that integrate and go beyond them: instruments systems.