Inspired by Hill and Hollans original work [7], we have been developing a theory of interaction history and building tools to apply this theory to navigation in a complex information space. We have built a series of tools - map, paths, annota- tions and signposts - based on a physical-world navigation metaphor. These tools have been in use for over a year. Our user study involved a controlled browse task and showed that users were able to get the same amount of work done with significantly less effort.

This article presents research—an experiment and the resulting prototype—on a method for treating gestural input so that it can be used for multimodal applications, such as interacting with virtual environments. This method involves the capture and use of natural , empty-hand gestures that are made during conventional descriptive utterances. Users are allowed to gesture in a normal continuous manner, rather than being restricted to a small set of discrete gestural commands as in most other systems. The gestures are captured and analyzed into a higher-level description. This description can be used by an application-specific interpreter to understand the gestural input in its proper context. Having a gesture analyzer of this sort enables natural gesture input to any appropriate application.

This paper describes a prototype system designed to meet the needs of the next generation of user interfaces. We address research questions of information complexity, multiple shared semantically-oriented views, and customizable tool environments. Our domain of interest is software systems that require interfaces for teams of people to large bodies of design artifacts. This prototype is built around the metaphor of tourists and tour guides.

The paper presents a formal structure for describing icons and their relations to objects. Icons are mappings from icon space, which deals with representational properties, to object space, which deals with computational objects. The nature of this mapping is formally described. An extension called automatic icons is proposed. The automatic-icon model subsumes currently-used static and animated icons and gives powerful and flexible new tools we call automatic icons. Some applications of automatic icons, and a tool built by the authors to help system designers create automatic icons, are described. The processes outlined in this paper are the subject of a pending patent.