May, Dean and Barnard (2003) used a theoretically based model to argue that objects in a wide range of interfaces should be collocated following screen changes such as a zoom-in to detail. Many existing online maps do not follow this principle, but move a clicked point to the centre of the subsequent display, leaving the user looking at an unrelated location. This paper presents three experiments showing that collocating the point clicked on a map so that the detailed location appears in the place previously occupied by the overview location makes the map easier to use, reducing eye movements and interaction duration. We discuss the benefit of basing design principles on theoretical models so that they can be applied to novel situations, and so designers can infer when to use and not use them.

Technological advances are increasing the use of dynamic or changing displays, in many forms of interface. The increasing amount of information held on the Internet and in private government and commercial databases also requires more innovative approaches to retrieval and browsing than existing text-based search engines can provide.

It has been suggested that computer interfaces could be made more usable if their designers utilized cinematography techniques, which have evolved to guide the viewer through a narrative despite frequent discontinuities in the presented scene (i.e., cuts between shots). Because of differences between the domains of film and interface design, it is not straightforward to understand how such techniques can be transferred. May and Barnard (1995) argued that a psychological model of watching film could support such a transference. This article presents an extended account of this model, which allows identification of the practice of collocation of objects of interest in the same screen position before and after a cut. To verify that filmmakers do, in fact, use such techniques successfully, eye movements were measured while participants watched the entirety of a commercially released motion picture, in its original theatrical format. For each of 10 classes of cut, predictions were made about the use of collocation. Peaks in eye movements between 160 and 280 msec after the cut were detected for 6 of the 10 classes, and results were broadly in line with collocation predictions, with two exceptions. It is concluded that filmmakers do successfully use collocation when cutting in and out from a detail, following the motion of an actor or object, and in showing the result of an action. The results are used to make concrete recommendations for interface designers from the theoretical analysis of film comprehension.

introduction Share on Introduction to multiple and collaborative tasks Authors: Peter Johnson University of Bath, Bath, UK University of Bath, Bath, UKView Profile , Jon May University of Sheffield, Sheffield, UK University of Sheffield, Sheffield, UKView Profile , Hilary Johnson University of Bath, Bath, UK University of Bath, Bath, UKView Profile Authors Info & Claims ACM Transactions on Computer-Human InteractionVolume 10Issue 4December 2003 pp 277–280https://doi.org/10.1145/966930.966931Published:01 December 2003Publication History 14citation1,520DownloadsMetricsTotal Citations14Total Downloads1,520Last 12 Months7Last 6 weeks1 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteGet Access

Now that technology allows us to present photorealistic animations of scenically lit objects acting in real‐time, the problem of computer graphics has changed from making displays recognisable, to ensuring that users notice what they are intended to see, without being distracted by irrelevant information. Worse than that, the use of veridical displays that are intended to be lifelike runs the risk of introducing unpredictable sources of information, that can lead users to infer all sorts of unwanted details. Traditional visual theory, based upon bottom‐up models of feature extraction from the retinal image, cannot inform us about these aspects of perception. Broader based cognitive theories are required that integrate visual perception with attention, memory, emotion and inference. Theories such as Barnard's Interacting Cognitive Subsystems enable phenomena such as change blindness and the craft principles of film editing to be interpreted within a common framework, supporting extrapolation to computer graphics.

A significant proportion of early HCI research was guided by one very clear vision: that the existing theory base in psychology and cognitive science could be developed to yield engineering tools for use in the interdisciplinary context of HCI design. While interface technologies and heuristic methods for behavioral evaluation have rapidly advanced in both capability and breadth of application, progress toward deeper theory has been modest, and some now believe it to be unnecessary. A case is presented for developing new forms of theory, based around generic “systems of interactors.” An overlapping, layered structure of macro- and microtheories could then serve an explanatory role, and could also bind together contributions from the different disciplines. Novel routes to formalizing and applying such theories provide a host of interesting and tractable problems for future basic research in HCI.

Now that technology allows us to present photorealistic animations of scenically lit objects acting in realtime, the problem of computer graphics has changed from making displays recognisable, to ensuring that users notice what they are intended to see, without being distracted by irrelevant information. Worse than that, the use of veridical displays that are intended to be lifelike runs the risk of introducing unpredictable sources of information, that can lead users to infer all sorts of unwanted details. Traditional visual theory, based upon bottom-up models of feature extraction from the retinal image, cannot inform us about these aspects of perception. Broader based cognitive theories are required that integrate visual perception with attention, memory, emotion and inference. Theories such as Barnard’s Interacting Cognitive Subsystems enable phenomena such as change blindness and the craft principles of film editing to be interpreted within a common framework, supporting extrapolation to computer graphics.

Although cognitive theory has been recognized as essential for the analysis of human–computer interaction (HCI), the representations that have been developed have been directed more toward theoretic purposes than practical application. To bridge the gap between theory and application, representations need to satisfy requirements for broad scope, a unified theoretical basis, and abstraction. Interacting cognitive subsystems (ICS) is proposed as a unified cognitive theory that can be used as the basis for such representations, and two approaches based on the theory are described. One entails the description of cognitive task models, which are a relatively complete representation of the cognitive activity required of a user in the coarse of an interaction. The other entails the production of less complete diagrammatic notations, which are intended to provide support in small-scale problem identification and resolution and which can be applied across tasks, visual interface, and sound interface issues and can handle static and dynamic situations. Although the former can be implemented in a production-rule expert system (ICSpert) and , therefore, does not require detailed modeling knowledge an the part of the analyst, the latter is a pencil-and-paper technique that does require theoretical knowledge but is intended to facilitate the acquisition of such knowledge in the interest of educating its users about the human aspects HCI. The representations differ in the knowledge required for their use, in the support that they offer, and in the situations for which they are appropriate. They have been used to represent problems from experimental situations, core HCI scenarios, a d red-world design projects. They share breadth of scope and abstraction, and their parent theory supports transfer of knowledge across domains of application and from older to newer technologies and feedback between the domain of application and the domain of theory.

User and system models typically are viewed as independent representations that provide complementary insights into aspects of human-computer interaction. Within system development, it is usual to see the 2 activities as separate, or at best loosely coupled, with either the design artifact or some third "mediatiag" expression providing the context in which the results of modelling can be related. This article proposes that formal system models can be combined directly with a representation of human cognition to yield an integrated view of human-system interaction: a syndetic model. Aspects of systems that affect usability then can be described and understood in terms of the conjoint behavior of user and computer. This article introduces and discusses, in syndetic terms, 2 scenarios with markedly different properties. We show how syndesis can provide a formal foundation for reasoning about interaction.

Claims are being made that videophone facilities on microcomputers allow transparent and effective use of shared work spaces by geographically separated colleagues. This can only be true if the video image helps the users understand each other's everyday speech. This study examines factors affecting the comprehension of deictic, gestural reference in videophone communication. Three camera positions were compared: the standard, 'face-to-face' view of the colleague, a 'reversed' view, and a rear three-quarters 'hind' view. Task conditions involved low referential ambiguity (where reference was verbally explicit as well as deictically indicated by gesture) and high referential ambiguity (deictic reference alone). The reference was either to an item in the workspace or a spatial relationship, and twodimensional and three-dimensional workspaces were compared. Results indicate that the standard face-to-face view found on many systems does not allow gestures made towards shared areas of the screen to be understood when the verbal information is ambiguous. In designing systems that encourage the use of normal patterns of speech, and hence the use of deictic reference, it is necessary to understand which cues are likely to resolve ambiguities, in which dimensions, and the extent to which the cues provided are likely to achieve that end.

As part of a collaborative long-term research project in human-computer interaction (HCI), the use of electronic archiving was studied by making pre-publication material available over the Internet, through anonymous FTP directories and pages on the World Wide Web. The archive was designed to fulfil two aims. First, it was a live experiment in computer supported co-operative work. Documents were no longer prepared and distributed in paper form but were made available electronically for use throughout the project. This resulted in substantial economies in the management of the project, virtually eliminating the need for routine mass duplication of all documents and minimizing postage, courier and facsimile costs. Second, the directories also appeared to function well in support of the rapid dissemination of our results to their potential users outside the project. Data on the use of the archive by project and non-project sites are presented here.

Certain design projects raise difficult user-interface problems that are not easily amenable to designers' intuition or rapid prototyping due to their novelty, conceptual complexity, and the difficulty of conducting appropriate user studies. Interpersonal access control in computer-mediated communication (CMC) systems is just such a problem. We describe a collection of systematic theory-based analyses of a system prototype that inherited its control mechanism from two preexisting systems. We demonstrate that the collective use of system and user modeling techniques provides insight into this complex design problem and enables us to examine the implications of design decisions for users and implementation. The analyses identify a number of weaknesses in the prototype and are used to propose ways of making substantive refinements to improve its simplicity and appropriateness for two tasks: altering one's accessibility and distinguishing between who can make what kinds of connections. We conclude with a discussion of some critical issues that are relevant for CMC systems, and reflect on the process of applying formal human-computer interaction (HCI) techniques in informal, exploratory design contexts.

The problem of developing software to meet precise specifications has lead to the development of mathematical notations for expressing and reasoning about the behaviour of a required or extant system. We describe a different use of formal models: as tools for gathering and consolidating requirements on interaction between engineered systems and their users. This change in focus reflects the growing use of sophisticated interactive technology in domains such as medicine, where human comfort or safety is an issue. Not only must software systems function correctly, but the demands that the interface places on users of those systems need to be understood. This problem cannot be addressed by formal models in isolation. Instead, we describe an approach that uses formal models of human information processing to augment models of system functions. As a result it becomes possible, at an early stage in system design, to consider the role of human cognition in the correct behaviour of the system.

The relevance of human-computer interaction to industry is being questioned, and the emphasis is shifting away from providing generalised support to systematic evaluation methods, typified by cognitive walkthroughs (CW). The evidence suggests that CW has not proved as effective as hoped. This evidence is examined, and the authors argue that the problem lies not with CW or its underlying theory in particular, but with its limited scope and in the increasing dissociation of an evaluation method from its theoretical foundation. Evaluation methods retaining a theoretical element would provide the necessary conceptual support to enable designers to identify, comprehend and resolve usability problems, and would also be less limited than dissociated evaluation methods in their breadth and depth of application. A vision of a ‘supportive evaluation’ tool is presented and cognitive task analysis (CTA), the methodology upon which a proof-of-concept tool has been based is described. Three brief design scenarios are described to illustrate how CTA supports the identification and resolution of usability problems and the role of cognitive modelling in the context of design is discussed.

Unless it is possible to use a broadband communications terminal for directly engaging in the tasks and activities which are important to the user (without the necessity of learning complex skills like those required to operate today's workstations) uptake will be restricted and usage will be inefficient. The enabling states approach, which distinguishes between the users' goal tasks, the states of the communication system which enable the performance of those tasks, and the enabling tasks required to create such enabling states, is described. The intention is to improve usability (and hence both uptake and usage) by designing interfaces that automatically identify and create the appropriate enabling states, allowing the user to concentrate on goal tasks rather than the enabling tasks. The approach is illustrated and discussed in the context of integrated broadband communication systems.>