Cognitive science normally takes the individual agent as its unit of analysis. In many human endeavors, however, the outcomes of interest are not determined entirely by the information processing properties of individuals. Nor can they be inferred from the properties of the individual agents, alone, no matter how detailed the knowledge of the properties of those individuals may be. In com-mercial aviation, for example, the successful completion of a flight is produced by a system that typically includes two or more pilots interacting with each other and with a suite of technological devices. This article presents a theoretical framework that tokes a distributed, socio-technical system rather than an indi-vidual mind as its primary unit of analysis. This framework is explicitly cognitive in that it is concerned with how information is represented and how representa-tions are transformed and propagated in the performance of tasks. An analysis of a memory task in the cockpit of a commercial airliner shows how the cognitive properties of such distributed systems can differ radically from the cognitive properties of the individuals who inhabit them. Thirty years of research in cognitive psychology and other areas of cognitive science have given us powerful models of the information processing prop-erties of individual human agents. The cognitive science approach provides a very useful frame for thinking about thinking. When this frame is applied to the individual human agent, one asks a set of questions about the mental An initial analysis of speed bugs as cognitive artifacts was completed in November of 1988. Since then, my knowledge of the actual uses of speed bugs and my understanding of their role in cockpit cognition has changed dramatically. Some of the ideas in this paper were presented

Users of synchronous groupware systems act both as individuals and as members of a group, and designers must try to support both roles. However, the requirements of individuals and groups often conflict, forcing designers to support one at the expense of the other. The tradeoff is particularly evident in the design of interaction techniques for shared workspaces. Individuals demand powerful and flexible means for interacting with the workspace and its artifacts, while groups require information about each other to maintain awareness. Although these conflicting requirements present real problems to designers, the tension can be reduced in some cases. We consider the tradeoff in three areas of groupware design: workspace navigation, artifact manipulation, and view representation. We show techniques such as multiple viewports, process feedthrough, action indicators, and view translations that support the needs of both individuals and groups.

Bookmarks are used as "personal Web information spaces" to help people remember and retrieve interesting Web pages. A study of personal Web information spaces surveyed 322 Web users and analyzed the bookmark archives of 50 Web users. The results of this study are used to address why people make bookmarks, and how they create, use, and organize them. Recommendations for improving the organization, visualization, representation, and integration of bookmarks are provided. The recommendations include simple mechanisms for filing bookmarks at creation time, the use of time-based visualizations with automated filters, the use of contextual information in representing bookmarks, and the combination of hierarchy formation and Web page authoring to aid in organizing and viewing bookmarks.

The rich person-to-person interaction afforded by shared physical workspaces allows people to maintain up-to-the minute knowledge about others ’ interaction with the workspace. This knowledge is workspace awareness, part of the glue that allows groups to collaborate effectively. In real-time groupware systems that provide a shared virtual workspace, the possibilities for interaction are impoverished when compared with physical workspaces, partly because support for workspace awareness has not generally been a priority in groupware design. In this paper, we present the concept of workspace awareness as one key to supporting the richness evident in face-to-face interaction. We construct a conceptual framework that describes the elements and mechanisms of workspace awareness, and then show several widgets that can be embedded in relaxed-WYSIWIS groupware systems to support the maintenance of workspace awareness.

In this paper we present a system that electromagnetically tracks the positions and orientations of multiple wireless objects on a tabletop display surface. The system offers two types of improvements over existing tracking approaches such as computer vision. First, the system tracks objects quickly and accurately without susceptibility to occlusion or changes in lighting conditions. Second, the tracked objects have state that can be modified by attaching physical dials and modifiers. The system can detect these changes in realtime. We present several new interaction techniques developed in the context of this system. Finally, we present two applications of the system: chemistry and system dynamics simulation. Keywords Tangible user interface, interactive surface, object tracking, two-handed manipulation, system dynamics, augmented reality

Complex design problems require more knowledge than any single person possesses because the knowledge relevant to a problem is usually distributed among stakeholders. Bringing different and often controversial points of view together to create a shared understanding among these stakeholders can lead to new insights, new ideas, and new artifacts. New media that allow owners of problems to contribute to framing and resolving complex design problems can extend the power of the individual human mind. Based on our past work and study of other approaches, systems, and collaborative and participatory processes, this article identifies challenges we see as the limiting factors for future collaborative human-computer systems. The Envisionment and Discovery Collaboratory (EDC) is introduced as an integrated physical and computational environment addressing some of these challenges. The vision behind the EDC shifts future development away from the computer as the focal point, toward an emphasis that tries to improve our understanding of the human, social, and cultural system that creates the context for use. This work is based on new conceptual principles that include creating shared understanding among various stakeholders, contextualizing information to the task at hand, and creating objects to think with in collaborative design activities.

Abstract. Traditionally, depictions and descriptions have been seen as complementary; depictions have been preferred to convey iconic or metaphorically iconic information whereas descriptions have been preferred for abstract information. Both are external representations designed to complement human memory and information processing. We have found the same underlying structure and semantics for route maps and route directions. Here we find that limited schematic map and direction toolkits are sufficient for constructing directions, supporting the possibility of automatic translation between them.

AbstractÐThis paper examines and proposes an approach to writing software specifications, based on research in systems theory, cognitive psychology, and human-machine interaction. The goal is to provide specifications that support human problem solving and the tasks that humans must perform in software development and evolution. A type of specification, called intent specifications, is constructed upon this underlying foundation. Index TermsÐRequirements, requirements specification, safety-critical software, software evolution, human-centered specifications, means-ends hierarchy, cognitive engineering.

This article proposes a theoretical framework for external representation based problem solving. The Tic-Tac-Toe and its isomorphs are used to illustrate the procedures of the framework as a methodology and test the predictions of the framework as a functional model. Experimental results show that the behavior in the Tic-Tac-Toe is determined by the directly available information in external and internal representations in terms of perceptual and cognitive biases, regardless of whether the biases are consistent with, inconsistent with, or irrelevant to the task. It is shown that external representations are not merely inputs and stimuli to the internal mind and that they have much more important functions than mere memory aids. A representational determinism is suggested--the form of a representation determines

The fundamental challenge for human-computer interaction (HCI) is to invent and design a culture in which humans can express themselves and engage in personally meaningful activities. Cultures are substantially defined by their media and tools for thinking, working, learning, and collaborating. New media change (1) the structure and contents of our interests, (2) the nature of our cognitive and physical tools, and (3) the social environment in which thoughts originate and evolve, and mindsets develop. Unfortunately, a large number of new media are designed from a perspective of seeing and treating humans primarily as consumers. The possibility for humans to be and to act as designers (in cases in which they desire to do so) should be accessible not only to a small group of high-tech scribes, but rather to all interested individuals and groups. 1. Introduction Cultures are substantially defined by their media and their tools for thinking, working, learning, and collaborating. A large...