Role of design guidelines in assisting the interface design task

Many human-computer interface design guidelines have been developed to design good interfaces for various kinds of software. Database systems have been also developed for accessing the guidelines. This paper considers the role of the design guidelines, rather than the role of the database, in improving interface designs. Sixteen software designers, who have no human factors experience, participated in a typical design review task. They were provided with a representation of a bad interface design. Eight designers (the UG participants) were instructed to individually improve the design by using the guidelines. The other designers (the NG participants) were instructed to improve it unaided (without the guidelines). The results indicated that both groups made similar numbers of improvements, but the UG participants produced higher quality improvements. Quality was evaluated using a goodness measure defined in this paper. The NG participants made good improvements but also bad ones that conflicted with the guidelines because only the designers' knowledge, experience and preference were used. On the other hand, the UG participants made fewer bad proposals because they could refer to the guidelines. Guidelines can work as a filter to eliminate inappropriate or false improvements from the designers' original proposals. There is a possibility that the guidelines may hinder the designer from developing new and interesting proposals. Their value is, however, very clear for novice designers who have no human factors experience; they can easily develop high quality proposals.