The paper argues that new approaches for delivering HCI knowledge from theory to designers will be necessary in the new millennium. First the progress made developing cognitive theories of interaction and their impact on the design process is reviewed. Direct application of current cognitive theories to design has been limited by scalability problems. This has led to bridging models that attempt to deliver insights from theory to design models in a more tractable manner. However, these too have met with limited success. An alternative is to represent HCI knowledge as claims and adopt the task-artefact approach to design in which theories are embedded in well-designed artefacts and explained to designers as psychologically motivated design rationale. Claims are proposed as a possible bridging representation that may enable theories to frame appropriate recommendations for designers and, vice versa, enable designers to ask appropriate questions for theoretical research. However, claims provide design advice grounded in specific scenarios and examples, which 1 limits their generality. Hence claims are their associated artefacts needs to be generalised so

The current variety of alternative approaches to usability evaluation methods (UEMs) designed to assess and improve usability in software systems is offset by a general lack of understanding of the capabilities and limitations of each. Practitioners need to know which methods are more effective and in what ways and for what purposes. However, UEMs cannot be evaluated and compared reliably because of the lack of standard criteria for comparison. In this article, we present a practical discussion of factors, comparison criteria, and UEM performance measures useful in studies comparing UEMs. In demonstrating the importance of developing appropriate UEM evaluation criteria, we offer operational definitions and possible measures of UEM performance. We highlight specific challenges that researchers and practitioners face in comparing UEMs and provide a point of departure for further discussion and refinement of the principles and techniques used to approach UEM evaluation and comparison. 1.

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

Abstract: We propose an interface design process compatible with scenario-based design methods, but specifically intended to facilitate three primary goals: design knowledge reuse, comparison of design products, and long-term research growth within HCI. This effort describes a computer-aided design tool suite, LINK-UP, which supports the design process for specific genre of systems that cross many domains—notification systems. We describe the vision for LINK-UP, contrasting underlying concepts with typical task-based modeling approaches. To achieve its stated goals, the design process is organized and guided by critical parameters, presenting several challenges that we reflect on through the results of a design simulation study. The possibilities envisioned through this approach have important implications for the integration of reusable design knowledge, HCI processes, and design support tools.

We elaborate a proposal for capturing, extending, and reusing design knowledge gleaned through usability testing. The proposal is specifically targeted to address interface design for notification systems, but its themes can be generalized to any constrained and well-defined genre of interactive system design. We reiterate arguments for and against using critical parameters to characterize user goals and usability artifacts. Responding to residual arguments, we suggest that clear advantages for research cohesion, design knowledge reuse, and HCI education are possible if several challenges are overcome. As a first step, we recommend a slight variation to the concept of a critical parameter, which would allow both abstract and concrete knowledge representation. With this concept, we demonstrate a feasible approach by introducing equations that elaborate and allow evolution of notification system critical parameters, which is made operational with a variety of usability evaluation instruments. A case study illustrates how one general instrument allowed system designs to be meaningfully compared and resulted in valuable inferences for interface reengineering. Broad implications and conclusions about this approach will be of interest to others concerned with using critical parameters in interface design, development of notification systems interfaces, or approaches to design rationale and knowledge reuse.

A prototype e-mail system was developed for cognitively disabled users, with four different interfaces (free format, idea prompt, form fill and menu driven). The interfaces differed in the level of support provided for the user and complexity of facilities for composing e-mail messages. Usability evaluation demonstrated that no one interface was superior because of individual differences in usability problems, although the majority of users preferred interfaces which did not restrict their freedom of expression (free format). In contrast to traditional evaluation studies, no common pattern of usability errors emerged, demonstrating the need for customisation of interfaces for individual cognitively disabled users. A framework for customising user interfaces to individual users is proposed, and usability principles derived from the study are expressed as claims following the task artefact cycle.

this paper, we present an empirical study of our use of scenario-based design in the

Scenarios of use support the integration of cognitive and organizational approaches to human-computer interaction (HCI) by providing a rich representation of activity from which cognitive and organizational perspectives can be developed. In this paper, a cognitive approach to scenario-based analysis and design one focused on causal relationships implicit in episodes of individual problem-solving and learning is extended by emphasizing an organizational work view of social causes and effects.

this article, we describe a framework for managing training evaluation in such contexts. We illustrate by example the feasibility of taking a broad approach toward training evaluation

Abstract: Through an examination of the emerging domain of cognitive systems, with a focus on attention-centric cognitive systems used for notification, this document explores the human-computer interaction challenges that must be addressed for successful interface design. This document asserts that with compatible tools and methods, user notification requirements and interface usability can be abstracted, expressed, and compared with critical parameter ratings; that is, even novice designers can assess attention cost factors to determine target parameter levels for new system development. With a general understanding of the user tasks supported by the notification system, a designer can access the repository of design knowledge for appropriate information and interaction design techniques (e.g., use of color, audio features, animation, screen size, transition of states, etc), which have analytically and empirically derived ratings. Furthermore, usability evaluation methods, provided to designers as part of the integrated system, are adaptable to specific combinations of targeted parameter levels. User testing results can be conveniently added back into the design knowledge repository and compared to target parameter levels to determine design success and build reusable HCI