The Grammar Lens: How Spatial Grammar Channels Interface Design

Abstract

The human information processing (HIPS) model predicts that people design by searching in a problem space, but the HIPS model alone provides insufficient guidance for system design. The eight generic tasks presented here elaborate the overall search task into sub-tasks that may be recombined in many different overall design processes. Supporting any such tasks and processes requires a notational system, for which the cognitive dimensions framework provides an analytic structure. Cognitive dimensions analysis requires descriptions of the activity undertaken, the notation used and the environment providing the notation and supporting the activity. We split the notation into two parts, one for design states and one for the design space. In addition we posit the notion of an interaction metaphor or lens that channels system (environment) designs in specific channels. We describe 25 grammar-based systems in cognitive dimensions terms, analyze them for their support of the eight generic exploration tasks and present a cognitive dimensions analysis for one conventional grammar-based system. The grammar lens for design exploration system appears to strongly channel system designs.