What Does Real Work Analysis Tell Us about System Design?

Human-computer interface design is explicitly or implicitly based on specific representations of the user's activity. Several strategies are used for system design. Some of them are based on "user's models" (for example: Cuff, 1980), which are not usually precise enough to predict the numerous difficulties in the system use. Others rely on general principles to elaborate command languages or to structure the man computer dialogue. These general principles may be: (a) the simplicity and coherence of the commands, (b) the "natural" aspect of the actions during dialogue, (c) the personalisation of the human-computer interface.