Claims for the virtues of visual programming languages have generally been strong, simple-minded statements that visual programs are inherently better than textual ones. They have paid scant attention to previous empirical literature showing difficulties in comprehending visual programs. This paper reports comparisons between the comprehensibility of textual and visual programs, drawing on the methods developed by Green (1977) for comparing detailed comprehensibility of conditional structures. The visual language studied was LabView, a circuit-diagram-like language which can express conditionals either as `forwards' structures (condition implies action, with nesting) or as `backwards' structures (action is governed by conditions, with boolean operators in place of nesting). Green (1977) found that forwards structures gave relatively better access to `sequential' information, and Gilmore and Green (1984) showed `backwards' structures gave relatively better access to `circumstantial' inf...

This paper describes a computational model of skilled use of a graphical user interface and of errors made by skilled users. The model is based of Norman's action framework and is implemented using Kintsch's construction-integration theory. The model selects actions, such as moving mouse cursor, clicking mouse button, typing letters, and so on, by integrating information from various sources. These sources include the display, task goals, expected device states, and knowledge about the interface and the application domain. We show how information about the intermediate states of a task presented on a display plays a critical role in skilled performance. The model also

This paper describes a computational model of skilled use of a graphical user interface based on Kintsch’s construction-integration theory [4, 8]. The model uses knowledge of a detailed representation of information on the display, a user’s goals and expectations, knowledge about the interface, and knowledge about the application domain to compute actions necessary to accomplish the user’s current goal. The model provides a well-motivated account of one kind of errors, action slips [14], made by skilled users. We show how information about the intermediate state of a task on the display plays a critical role in skilled performance, i.e., display-based problem solving [10].

In this paper, we present a new approach to interaction modelling based on the concept of information resource. The approach is inspired by recent distributed cognition (DC) literature but develops a model that applies specifically to human-computer interaction (HCI) modelling. There are of course many approaches to modelling HCI and the motivation of this paper is not to offer yet another approach. Rather our motivation is that the recent developments in DC are so obviously relevant to HCI modelling and design yet the ideas have lacked visibility in the HCI community. By providing a model whose concepts are rooted in DC concepts we hope to achieve this visibility. In addition, we hope to provide the foundation for a programme of research that extends the DC analysis of single user systems presented here to larger units of analysis more familiar to CSCW and DC research. DC research identifies resources for action as central to the interaction between people and technologies, but it sto...

The history of psychological explanation in human–computer interaction (HCI) is reviewed in order to illustrate the notion of cyclic interaction. The claim made is that much real behaviour is usefully thought of as a continuous process of cyclic interaction with the environment. According to this account action leads to changes to the state of the world, these are evaluated with respect to, and in a manner conditioned by, the user’s current goals. This evaluation leads to the reformulation of goals and further action, this action leads to a new state of the environment, and so on. Cyclic interaction is contrasted with the more commonly adopted view of cognition that may be caricatured as a ‘one-shot comprehension ’ where perception and recognition lead to action but the role of goals and the effects of action on the environment are not primary concerns. It is argued that a change of emphasis in cognitive research is required to make good these omissions, with new kinds of experimental paradigm and new ways of modelling behaviour. © 1998 Elsevier Science B.V. All rights reserved

Abstract: This paper addresses the use of artefacts as a powerful resource for analysis, focusing on the 'artefact as designed ' as a means of eliciting the designers ' explicit and implicit knowledge and 'artefacts as used ' as a means of uncovering the trail left by currently inactive processes. Artefact analysis is particularly suitable in situations where direct observation is ineffective, especially in activities that occur infrequently. We demonstrate the usefulness of our technique through the analysis of artefacts within both the office and the meeting environment. This is part of a wider study aimed at understanding the nature of decisions in meetings with the view of producing a tool to aid decision management and hence reduce rework. We conclude by drawing out some general lessons from our analysis, which reaffirms the intricate role that artefacts play in maintaining activity dynamics.

In this article we wish to describe an approach to modelling human-computer interaction (HCI) based on recent theoretical developments in cognitive science, namely distributed cognition research (DC). There are of course many approaches to modelling HCI ranging from task-oriented models to so-called contextualised models such as Activity Theory. The motivation of this paper is not to provide just another approach but rather to offer an approach which spans some of this range while remaining relatively comprehensible in its theoretical foundations. A second motivation is that the recent theoretical developments in DC already alluded to are so obviously relevant to HCI theory and design but the ideas have lacked visibility in the HCI community. Distributed Cognition research, while identifying resources for action as central to the interaction between people and technologies, stops short of providing a model of such resources. The resources model described in this paper defines a limited...

This paper addresses the use of artefacts as a resource for analysis. Artefacts are particularly useful in situations where direct observation is ineffective, in particular for infrequent activities. We discuss two classes of techniques: focusing on the 'artefact as designed' as a means of recovering designers' explicit and implicit knowledge and 'artefacts as used' as a means of uncovering the trail left by currently inactive processes. These techniques have been applied using a meeting capture system and meeting minutes as the artefact resources. This is part of a wider study to understand the nature of decisions and so reduce rework.

This report proposes research with two goals. Firstly, to investigate how effective software visualizations can be designed and evaluated. Secondly, by building software visualizations for persistent programming environments to demonstrate these techniques, to understand the relationship between persistence and software visualization. The software visualization literature has been reviewed. It was found to provide very little guidance to the design of visualizations, and makes little consideration of users and their tasks both in the products it produces and the taxonomies it offers. Human-Computer Interaction (HCI) offers the techniques of design principles, analytic evaluation and empirical evaluation for the design and evaluation of effective interactive systems. Their applicability to the design and evaluation of software visualization is reviewed. Analytic evaluation was found to be unsuitable for software visualization because it focuses on the input side of interaction, for exam...

In this paper, we present a new approach to interaction modelling based on the concept of information resource. The approach is inspired by distributed cognition literature but develops a model which applies specifically to human-computer interaction (H-CI) modelling. A number of information resources are described. These resources can be represented internally or externally and can find different expressions when represented externally. The distribution of resources and the properties of their expressions are what shape interaction. The resource model is exemplified by analysing an episode from a Macintosh interaction. Keywords H-CI modelling, distributed cognition, design, evaluation PLAN-BASED THEORIES IN H-CI Within both the science and engineering of H-CI, most models of interaction are plan-based. Norman's (1988) well known goal-plan-execute-evaluate cycle is perhaps the most widely cited example and has been used to consider design issues like the so-called gulf of executio...