The cognitive dimensions framework is a broad-brush evaluation technique for interactive devices and for non-interactive notations. It sets out a small vocabulary of terms designed to capture the cognitively-relevant aspects of structure, and shows how they can be traded off against each other. The purpose of this paper is to propose the framework as an evaluation technique for visual programming environments. We apply it to two commercially-available dataflow languages (with further examples from other systems) and conclude that it is effective and insightful; other HCI-based evaluation techniques focus on different aspects and would make good complements. Insofar as the examples we used are representative, current VPLs are successful in achieving a good `closeness of match', but designers need to consider the `viscosity' (resistance to local change) and the `secondary notation' (possibility of conveying extra meaning by choice of layout, colour, etc.).

. The proliferation ofcomputing into the physical world promises more than the ubiquitous availability of computing infrastructure; it suggests new paradigms of interaction inspired by constant access to information and computational capabilities. For the past decade, applicationdriven research in ubicomp has pushed three interaction themes: natural interfaces, context-aware applications, and automated capture and access. To chart a course for future research in ubiquitous computing, we review the accomplishments of these efforts and point to remaining research challenges. Research in ubiquitous computing implicitly requires addressing some notion of scale; whether in the number and type of devices, the physical space of distributed computing or the number of people using a system. We posit a new area of applications research, everyday computing, focussed on scaling interaction with respect to time. Just as pushing the availability of computing away from the traditional desktop fun...

this paper, I review the history of HCI as steps toward a science of design. My touchstone is Simon's (1969) provocative book he Sciences of the Artificial. The book pre-dates HCI, and many of its specific characterizations and claims about design are no longer authoritative (see Ehn, 1988). Nevertheless, two of Simon's themes echo through the history of HCI, and still provide guidance for charting its continuing development

this article was given at ECOOP '93.

Abstract: In this paper, we recruit the construct of psychological design rationale as a framework for integrating theory development with design evaluation in HCI. We propose that, in some cases, part of an artifact’s psychological design rationale can be regarded as inherited from second-order artifacts (prescriptive design models, architectures and genres, tools and environments, interface styles). We show how evaluation data pertaining to an artifact can be used to test and develop the second-order artifacts from which it inherits. 1.

Data modelling reveals the internal structure of an information system, abstracting away from details of the physical representation. We show that entity-relationship modelling, a well-tried example of a data-modelling technique, can be applied to both interactive and non-interactive information artefacts in the domain of HCI. By extending the conventional ER notation slightly (to give ERMIA, Entity-Relationship Modelling for Information Artefacts) it can be used to describe differences between different representations of the same information, differences between user's conceptual models of the same device, and the structure and update requirements of distributed information in a worksystem. It also yields symbolic-level estimates of Card et al.'s (1994) index of `cost-of-knowledge' in an informa- tion structure, plus a novel index, the `cost-of-update'; these symbolic estimates offer a useful complement to the highly detailed analyses of time costs obtainable from GOMS-like...

Many efforts have been made to exploit the properties of graphical notations to support argument construction and communication. In the context of design rationale capture, we are interested in graphical argumentation structures as cognitive tools to support individual and collaborative design in real time. This context of use requires a detailed understanding of how a new representational structure integrates into the cognitive and discursive flow of design, that is, whether it provides supportive or intrusive structure. This paper presents a use-oriented analysis of a graphical argumentation notation (QOC). Through a series of empirical studies, we show that it provides most support when elaborating poorly understood design spaces, but is a distraction when evaluating well constrained design spaces. This is explained in terms of the cognitive compatibility between argumentative reasoning and the demands of different modes of designing. We then provide an account based the collaborative affordances of QOC in group design meetings, and extend this to discuss the evolution of QOC argumentation from short term working memory to long term group memory.

A design rationale (DR) is a representation of the reasoning behind the design of an artifact. In recent years, the use of semiformal notations for organising arguments about design decisions has attracted much interest within the software engineering and human-computer interaction communities, leading to the development of a number of DR notations and tool environments. This article begins by reviewing the motivation for expressing DR as design argumentation, and then surveys evidence from design studies to show when and how it can be productive to construct explicit design argumentation during design. The article then discusses practical cognitive, organizational and technological factors which could facilitate the uptake of design rationale systems. Keywords: design rationale, argumentation, process-oriented software engineering, organizational memory, computer-supported collaborative work I. The idea of design rationale A design rationale (DR) expresses elements of the reasoning ...

A few representations have been used for capturing design rationale. It is important to know in what ways they are adequate or limited so that we know how to improve them. In this paper, we develop a framework for evaluating design rationale representations based on a set of generic design tasks. We build the framework by progressively differentiating the elements of design rationale that, when made explicit, support an increasing number of the design tasks. With this framework, we evaluate the expressiveness of the existing representations. We also present a language, DRL, that we believe is the most expressive of the existing representations without being too complex for human users. We also discuss the limitations of DRL as open problems for further research.

Interaction. Please do not cite or circulate without permission from the authors. A computer system does not itself express the motivations that initiated its design, the user requirements it was intended to address, the discussions, debates and negotiations that determined its organization, the reasons for its particular features, the reasons against features it does not have, the weighing of tradeoffs, and so forth. This information comprises the design rationale of the system. It can be critical to the many stakeholders in a design process: customers, users, service providers, and marketers, as well as designers who want to build upon the system and the ideas it embodies. Design rationale can contribute to theory development in HCI in three ways. First, it provides a foundation for ecological science in HCI by describing the decisions and implicit causal relationships embodied in HCI artifacts. Second, it provides a foundation for action science in HCI by integrating activities directed at description and understanding with those directed at design and development. Finally, it provides a framework for a synthetic science of HCI in which the insights and predictions of diverse technical theories can be integrated. The preceding chapters illustrated how theoretical concepts and methods from a variety of sciences are used to gain insight in the context of HCI design and evaluation. This chapter inverts that train of thought to some extent. It shows how reflective HCI design practices — involving design rationale documentation and analysis — can be used (1) to closely couple theoretical concepts and methods with the designed artifacts that instantiate them, (2) to more closely integrate theory application and theory development in design work, and (3) to more broadly integrate the insights of different technical theories. 1.