User interface issues raised by knowledge refinement

The concept of ease of use has evolved over the last 30 years, keeping pace with developments in user interface technology, in the manner of Carroll's task-artifact cycle. This paper argues that recent developments in knowledge engineering require yet further changes in the concept and discusses what implications they might have for user interface design. The development in question is that construction of knowledge bases is, in many cases, no longer a matter of assembling pieces of knowledge that have been made available by knowledge acquisition, but takes on the nature of creative design which results in the generation of new knowledge at the user interface, A key difference is that while knowledge base assembly can be seen as a series of discrete events, creative design is more of a continuous process in which the user's flow of thinking must not be interrupted. This means that traditional WIMP and GUI interfaces are no longer appropriate and a more ''proximal'' form must be found. (C) 1996 Academic Press Limited.