An investigation of the representations of users' requirements in the design of interactive systems

The design of interactive computer systems was identified as an important area for investigation due to the increasing evidence of a discrepancy between the intended use of the systems, and the use by users. This led to the hypothesis that the discrepancies between systems and users were attributed to an inadequate representation of users' requirements in the design of the systems. Therefore, the research focused on the design process, and how users' requirements were represented in the process. The research was based on an investigation of two areas of design: the type of design processes that developed in system design, and the representations of users' requirements in design. Studies were based on structured interviews with designers, on observations of design teams engaged in design tasks, and on documentation from design projects. A major component of the research findings concerns the design context. The research has made it possible to see how the variations in design relate to the context in which it takes place. Some of the primary contextual influences include the commercial constraint, the pressure to innovate, and the specialisation in user interface design. Another significant finding relates to the representations of users' requirements in the design process. Two key issues emerge from the findings. First, designers approach design tasks with a technical, system based design model. The application of this model to design tasks is often inappropriate; however, designers lack design schemas appropriate to user related tasks. The second issue is that designers often work with inadequate information on users' requirements. The design process is characterised by limitations of information on users' information in design tasks. The extent to which these limitations are experienced by designers differs according to the design context.