COGNITIVE SUPPORT - DESIGNING AIDING TO SUPPLEMENT HUMAN KNOWLEDGE

This article advocates, as alternative for either the ''classical'' te chnology- or user-centred approach, to focus on the joint human-comput er task performance in system design. Human involvement can be improve d by designing system functions which complement human knowledge and c apacities. Based on general needs for cognitive support, an aiding fun ction is proposed which-in the process of task execution-takes the ini tiative to present context-specific, procedural task knowledge. Design of such aiding comprises two aspects: design of software and design o f a human-computer system. Modern model-based software engineering met hods provide strong support for the design of software systems, but li ttle support for modelling the human-computer interaction. Current mod el-based methods are extended to address human-computer interaction is sues. The resulting method comprises the design of easy-to-use-and-lea rn interfaces providing, if needed, aiding. In a case study, the metho d is applied to design a conventional plain interface and an aiding in terface for the statistical program HOMALS. In an experiment, users wi th minor HOMALS expertise prove to perform their tasks better and to l earn more with the aiding interface.