Human-Computer Interaction

Published by Taylor & Francis
Online ISSN: 1532-7051
Print ISSN: 0737-0024
Publications
The conceptual design of a comprehensive support system for operators of complex systems is presented. Key functions within the support system architecture include information management, error monitoring, and adaptive aiding. One of the central knowledge bases underlying this functionality is an operator model that involves a 'matrix' of algorithmic and symbolic models for assessing and predicting an operator's activities, awareness resources, intentions, and performance. Functional block diagrams are presented for the overall architecture as well as the key elements within this architecture. A variety of difficult design issues are discussed and ongoing efforts aimed at resolving these issues are noted.
 
This article presents a cognitively oriented viewpoint on design. It focuses on cognitive, dynamic aspects of real design, i.e., the actual cognitive activity implemented by designers during their work on professional design projects. Rather than conceiving de-signing as problem solving - Simon's symbolic information processing (SIP) approach - or as a reflective practice or some other form of situated activity - the situativity (SIT) approach - we consider that, from a cognitive viewpoint, designing is most appropriately characterised as a construction of representations. After a critical discussion of the SIP and SIT approaches to design, we present our view-point. This presentation concerns the evolving nature of representations regarding levels of abstraction and degrees of precision, the function of external representations, and specific qualities of representation in collective design. Designing is described at three levels: the organisation of the activity, its strategies, and its design-representation construction activities (different ways to generate, trans-form, and evaluate representations). Even if we adopt a "generic design" stance, we claim that design can take different forms depending on the nature of the artefact, and we propose some candidates for dimensions that allow a distinction to be made between these forms of design. We discuss the potential specificity of HCI design, and the lack of cognitive design research occupied with the quality of design. We close our discussion of representational structures and activities by an outline of some directions regarding their functional linkages.
 
levels at which methods are defined; number of times a given situation has been observed by subject  
a. Total number of modifications made in the class model.  
b. Number of method modifications made in the class model.  
An empirical study was conducted to analyse design strategies and knowledge used in object-oriented software design. Eight professional programmers experienced with procedural programming languages and either experienced or not experienced in object-oriented design strategies related to two central aspects of the object-oriented paradigm: (1) associating actions, i.e., execution steps, of a complex plan to different objects and revising a complex plan, and (2) defining simple plans at different levels in the class hierarchy. As regards the development of complex plans elements attached to different objects, our results show that, for beginners in OOP, the description of objects and the description of actions are not always integrated in an early design phase, particularly for the declarative problem whereas, for the programmers experienced in OOP, the description of objects and the description of actions tend to be integrated in their first drafts of solutions whichever the problem type. The analysis of design strategies reveal the use of different knowledge according to subjects' language experience: (1) schemas related to procedural languages; actions are organized in an execution order, or (2) schemas related to object-oriented languages; actions and objects are integrated, and actions are organised around objects.
 
Study I: Clustering of the Watched survey responses to the seven context-of-use questions. This graph represents only the 294 individuals who did not give the same response for all seven context-of-use questions. Percent agreement (within subject): The lines represent links between questions or clusters of questions; the roman numerals represent the order in which the links were established. When two individual variables are linked together, the values on the vertical axis represent the percentage of individuals who gave the same answer (within subject) to the two questions. When two clusters of questions are linked together, the values represent the percentage of within-subject agreement for the two most similar questions from the two clusters.
Study II: Percentage of Justification Use (Averaged Across the 7 Context-of-Use Questions) for The Watcher Large Display and The Watched Interview Responses by Evaluation, Stakeholder Role [W'er = Watcher; W'ed = Watched] and Gender.
(Continued)
Digitally capturing and displaying real-time images of people in public places raises concerns for individual privacy. Applying the principles of Value Sensitive Design, we conducted two studies of people's social judgments about this topic. In Study I, 750 people were surveyed as they walked through a public plaza that was being captured by a HDTV camera and displayed in real-time in the office of a building overlooking the plaza. In Study II, 120 individuals were interviewed about the same topic. Moreover, Study II controlled for whether the participant was a direct stakeholder of the technology (inside the office watching people on the HDTV large-plasma display window) or an indirect stakeholder (being watched in the public venue). Taking both studies together, results (showed the following): (a) the majority of participants upheld some modicum of privacy in public; (b) people's privacy judgments were not a one-dimensional construct, but often involved considerations based on physical harm, psychological well-being, and informed consent; and (c) more women than men expressed concerns about the installation, and, unlike the men, equally brought forward their concerns, whether they were The Watcher or The Watched.
 
This essay considers the problem of defining the context that context aware systems should pay attention to from a human perspective. In particular, we argue that there are human aspects of context that cannot be sensed or even inferred by technological means, so context aware systems cannot be designed simply to act on our behalf. Rather they will have to be able to defer to users in an efficient and non-obtrusive fashion. Our point is particularly relevant for systems that are constructed such that applications are architecturally isolated from the sensing and inferencing that governs their behavior. We propose a design framework that is intended to guide thinking about accommodating human aspects of context. This framework presents four design principles that support intelligibility of system behavior and accountability of human users and a number of human-salient details of context that must be accounted for in context aware system design. CONTENTS 2. HUMAN CONSIDERATIONS IN CONTEXT 2.1. Basic Context Awareness -- Responsiveness to the Environment 2.2. Human Aspects of Context -- Responsiveness to People 2.3. Social Aspects of Context -- Responsiveness to the Interpersonal 2.4. Summary 3. A FRAMEWORK FOR INTELLIGIBILITY AND ACCOUNTABILITY IN CONTEXT AWARE SYSTEMS 3.1. Four Design Principles and Human-Salient Details Required to Realize Them 3.1.1. Context aware principles to support intelligibility and accountability 3.1.2. Human salient details of context 3.2. Applying the Principles 3.2.1. Inform the user of current contextual system capabilities and understandings 3.2.2. Provide feedback 3.2.3. Enforce identity and action disclosure 3.2.4. Provide user control (BODY OF ESSAY) Imagine you are in a context aware building recording verbal input to some document....
 
We identify a problem with the process of research in the HCI community -- an overemphasis on "radical invention" at the price of achieving a common research focus. Without such a focus, it is difficult to build on previous work, to compare different interaction techniques objectively, and to make progress in developing theory. These problems at the research level have implications for practice, too
 
This article shows how the concept of affordance in the user interface fits into a well-understood artificial intelligence (AI) model of acting in an environment. In this model AI planning research is used to interpret affordances in terms of the costs associated with the generation and execution of operators in a plan. We motivate our approach with a brief survey of the affordance literature and its connections to the planning literature, and then explore its implications through examples of common user interface mechanisms described in affordance terms. Despite its simplicity, our modeling approach ties together several different threads of practical and theoretical work on affordance into a single conceptual framework. # St. Amant is a computer scientist with an interest in artificial intelligence and complex interactive systems; he is an Assistant Professor in the Department of Computer Science at North Carolina State University. 1 Affordances in a planning representation 2 Con...
 
presents
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...
 
Object-oriented (OO) technology has been heralded as a solution to the problems of software engineering. The claims are that OO technology promotes understandability, extensibility, evolvability, reusability, and maintainability of systems, and that OO systems are easy to understand and use. However, this technology has not been as successful as expected. An analysis of experiences and empirical studies reveals that the problem is not the technology per se, but rather that the technology provides no support to software developers in performing the processes the technology requires. We present a cognitive model of software development that details the challenges software developers face in using OO technology. The model focuses on three aspects of software development: evolution, reuse and redesign, and domain orientation. We motivate this model with a variety of first-hand experiences and use it to assess current OO technology. Further, we present tools and evaluations that substantiat...
 
This article provides an overview of the EPIC architecture being developed by Kieras and Meyer for modeling human cognition and performance (Kieras, Wood, & Meyer, 1997; Meyer & Kieras, 1997a, 1997b). EPIC is similar in spirit to the Model Human Processor (MHP; Card, Moran, & Newell, 1983), but EPIC incorporates many recent theoretical and empiri- cal results about human performance in the form of a software framework for computer simulation modeling. Using EPIC, a model can be con- structed that represents the general procedures required to perform a complex multimodal task a a set of production rules. When the model is supplied with the external stimuli for a specffic task, it will then execute the procedures in whatever way the task requires, thus simulating a human 's performing the task and generating the predicted actions in simulated real time. EPIC is an architecture for constructing models of 394 performance. It is notet a learning system and so has no mechanisms for learning how to perform a task. Rather, the purpose of EPIC is to repre- sent in detail the perceptual, motor, and cognitive constraints on the human ability to perform tasks
 
Building truly "context-aware" environments presents a greater challenge than using data transmitted by ubiquitous computing devices: it requires shared understanding between humans and their computational environments. This essay articulates some specific problems that can be addressed by representing context. It explores the unique possibilities of design environments that model and represent domains, tasks, design guidelines, solutions and their rationale, and the larger context of such environments embedded in the physical world. Context in design is not a fixed entity sensed by devices, but it is emerging and it is unbounded. Context-aware environments must address these challenges to be more supportive to all stakeholders who design and evolve complex design artifacts. Gerhard Fischer 2 HCI Journal "Context-Aware Computing" Contents Articulating the Task at Hand and Making Information Relevant to It ____________ 1
 
While graphical interfaces have provided a host of advantages to the majority of computer users, they have created a significant barrier to blind computer users. To meet the needs of these users, a methodology for transforming graphical interfaces into nonvisual interfaces has been developed. In this design, the salient components of graphical interfaces are transformed into auditory interfaces. Based on a hierarchical model of the graphical interface, the auditory interface utilizes auditory icons to convey interface objects. Users navigate the interface by traversing its hierarchical structure. This design results in a usable interface that meets the needs of blind users while providing many of the benefits of graphical interfaces. 2 1. INTRODUCTION 2. BACKGROUND 2.1. The GUI Problem 2.2. Requirements for GUI Access by Blind Users 2.3. Evaluation of Screen Reader Interfaces 3. MODELING GRAPHICAL INTERFACES 3.1. Determining the Contents of the Interface Transformation What are...
 
The Context Toolkit (Dey, Salber, and Abowd 2001 [this special issue]) is only one of many possible architectures for supporting context-aware applications. In this essay, we look at the trade-offs involved with a service infrastructure approach to context-aware computing. We describe the advantages that a service infrastructure for contextawareness has over other approaches, outline some of the core technical challenges that must be addressed before such an infrastructure can be built, and point out promising research directions for overcoming these challenges. CONTENTS 1. INTRODUCTION 2. LIBRARIES, FRAMEWORKS, TOOLKITS, AND INFRASTRUCTURES 3. ADVANTAGES TO AN INFRASTRUCTURE APPROACH 3.1. Independence from Hardware, Operating System, and Programming Language 3.2. Improved Capabilities for Maintenance and Evolution 3.3. Sharing of Sensors, Processing Power, Data, and Services 4. CHALLENGES TO BUILDING A CONTEXT-AWARE INFRASTRUCTURE 4.1. Defining Standard Data Formats and Protocols 4...
 
Computing devices and applications are now used beyond the desktop, in diverse environments, and this trend toward ubiquitous computing is accelerating. One challenge that remains in this emerging research field is the ability to enhance the behavior of any application by informing it of the context of its use. By context, we refer to any information that characterizes a situation related to the interaction between humans, applications and the surrounding environment. Context-aware applications promise richer and easier interaction, but the current state of research in this field is still far removed from that vision. This is due to three main problems: (1) the notion of context is still ill defined; (2) there is a lack of conceptual models and methods to help drive the design of context-aware applications; and (3) no tools are available to jump-start the development of context-aware applications. In this paper, we address these three problems in turn. We first define context, identify categories of contextual information, and characterize context-aware application behavior. Though the full impact of context-aware computing requires understanding very subtle and high-level notions of context, we are focusing our efforts on the pieces of context that can be inferred automatically from sensors in a physical environment. We then present a conceptual framework that separates the acquisition and representation of context from the delivery and reaction to context by a contextaware application. We have built a toolkit, the Context Toolkit, that instantiates this conceptual framework and supports the rapid development of a rich space of context-aware applications. We illustrate the usefulness of the conceptual framework by describing a number of contextaware applications that h...
 
Context-aware computing is generally associated with elements of the Ubiquitous Computing program, and the opportunity to distribute computation and interaction through the environment rather than concentrating it at the desktop computer. However, issues of context have also been important in other areas of HCI research. I argue that the scope of context-based computing should be extended to include not only Ubiquitous Computing, but also recent trends in tangible interfaces as well as work on sociological investigations of the organization of interactive behavior. By taking a view of contextaware computing that integrates these different perspectives, we can begin to understand the foundational relationships that tie them all together, and that provide a framework for understanding the basic principles behind these various forms of embodied interaction. In particular, I point to phenomenology as a basis for the development of a new framework for design and evaluation of context-aware ...
 
A source of intellectual overhead periodically encountered by scientists is the call to be "hard," to insure good science by imposing severe methodological strictures. Newell and Card (1985) have undertaken to impose such strictures on the psychology of humancomputer interaction. Although their discussion contributes to theoretical debate in humancomputer interaction by setting a reference point, their specific argument fails. Their program is unmotivated, is severely limited, and suffers from these limitations in principle. A top priority for the psychology of human-computer interaction should be the articulation of an alternative explanatory program, one that takes as its starting point the need to understand the real problems involved in providing better computer tools for people to use. 1. Newell and Card on Being Hard Newell and Card (1985) have presented a program for psychological research in humancomputer interaction couched as an analysis of how psychology can avoid being ...
 
Over the last 10 years, Computer-Supported Cooperative Work (CSCW) has identified a base set of findings. These findings are taken almost as assumptions within the field. In summary, they argue that human activity is highly flexible, nuanced, and contextualized and that computational entities such as information transfer, roles, and policies need to be similarly flexible, nuanced, and contextualized. However, current systems cannot fully support the social world uncovered by these findings. This paper argues that there is an inherent gap between the social requirements of CSCW and its technical mechanisms. The social-technical gap is the divide between what we know we must support socially and what we can support technically. Exploring, understanding, and hopefully ameliorating this social-technical gap is the central challenge for CSCW as a field and one of the central problems for HCI. Indeed, merely attesting the continued centrality of this gap could be one of the important intell...
 
This paper is concerned with how to represent in system design the kinds of features of work settings as reported by ethnographic studies of work. Various researchers and practitioners have found that ethnomethodological analyses of work settings can provide useful insights to the work processes and settings that system design is interested in. Previously at Lancaster, we have examined ways in which ethnography can be used in the design process, and how the results of ethnographic analyses can be presented in such a way as to be useful components of the design process. This paper reflects an effort to approach these methodological issues from a different perspective, by examining how the lessons learned from ethnographic studies can be reflected in the design process itself, and in particular how design artefacts (models, documents, etc.) can express the type of information which ethnographic studies produce. The paper focuses on how ethnographic analyses can influence the main repres...
 
The conceptual basis for designing procedures is confused by the problematics of characterising a relationship between procedures and work practices. As they emerge from scientific management theory, procedures connote a means of rationalising and controlling work. However, interpretations of the use of procedures reveal differences in emphasis on the work required to relate procedures to practice, from comprehending to evaluating appropriateness or reasonableness. These evaluations point to a moral character in this work which we characterise in terms of workers' concerns. Moreover, as conceptual differences in emphasis such as these can prove intractable, we argue that a more productive approach to resolving the problematics would be to evaluate the usefulness of a sensitivity to concerns in designing procedures. Three brief case studies of the use of procedures in safety critical settings point to workers making judgements when relating procedures to their practice, including judgem...
 
Technology development in HCI can be interpreted as a co-evolution of tasks and artifacts. The tasks people actually engage in (successfully or problematically) and those they wish to engage in (or perhaps merely to imagine) define requirements for future technology, and specifically for new HCI artifacts. These artifacts, in turn, open up new possibilities for human tasks, new ways to do familiar things, entirely new kinds of things to do. In this paper we describe psychological design rationale as an approach to augmenting HCI technology development and to clarifying the sense in which HCI artifacts embody psychological theory. A psychological design rationale is an enumeration of the psychological claims embodied by an artifact for the situations in which it is used. As an example, we present our design work with the View Matcher, a Smalltalk programming environment for coordinating multiple views of an example application. In particular, we show how psychological design rationale was used to develop a view matcher for code reuse from prior design rationales for related programming tasks and environments. 1. TASKS AND ARTIFACTS In 1605, Sir Francis Bacon called for a "natural history of trades." He urged that technical tools, techniques and processes be made more public and explicit. This was one element in his broader project of developing practical science, and hinged on the assumption that if such knowledge could be more systematically considered and integrated, human progress would necessarily result. Thus, Bacon suggested that new concepts and inventions would result "by a connexion and transferring of the observations of one Arte, to the use of another, when the experiences of several misteries shall fall under the consideration of one man's minde."(1970: Book...
 
This paper first explores the knowledge management problem in more detail and discuss challenges to acquiring, maintaining, and disseminating design knowledge. We then describe a framework for integrating a design memory tool Human-Computer Interaction, , 10, 1 (1995), 1-38.
 
This commentary reviews the existing research literature concerning support for talking about objects in mediated communication, drawing three conclusions: (a) speech alone is often sufficient for effective conversations; (b) visual information about work objects is generally more valuable than visual information about work participants; (c) disjoint visual perspectives can undermine communication processes. I then comment on the four papers in the light of these observations, arguing that they broadly support these observations. I discuss the paradoxical failure of current technologies to support talk about objects, arguing that these need to be better integrated with existing communication applications. I conclude by outlining a research agenda for supporting talk about things, identifying outstanding theoretical, empirical and design issues.
 
This paper describes a comprehension-based model of how experienced Macintosh users learn a new application by doing a task presented as a series of exercises. A comprehension mechanism transforms written instructions into goals that control an action planning process proposed by Kitajima and Polson (11). The transformation process is based on a theory of solving word problems developed by Kintsch (8,9). The comprehension and action planning processes define constraints on the wording of effective instructions. The combined model is evaluated using data from Franzke (3). We discuss implications of these results for Minimalist Instructions (1) and Cognitive Walkthroughs (17).
 
The usability of IT security management (ITSM) tools is hard to evaluate by regular methods, making heuristic evaluation attractive. However, standard usability heuristics are hard to apply as IT security management occurs within a complex and collaborative context that involves diverse stakeholders. We propose a set of ITSM usability heuristics that are based on activity theory, are supported by prior research, and consider the complex and cooperative nature of security management. In a between-subjects study, we compared the employment of the ITSM and Nielsen's heuristics for evaluation of a commercial identity management system. Participants who used the ITSM set found more problems categorized as severe than those who used Nielsen's. As evaluators identified different types of problems with the two sets of heuristics, we recommend employing both the ITSM and Nielsen's heuristics during evaluation of ITSM tools.
 
The research reported in this article provides descriptions of design activities and of the evolving designs for expert procedural and expert object-oriented (OO) designers and for novice OO designers who also had extensive procedural experience. Ten experienced programmers were observed while designing software that would serve as a scoring system for swim meet competitions. Talk-aloud protocols were collected and analyzed for different types of cognitive activities and strategies that occurred during the course of design. In particular, we analyzed both the design activities and the level of abstraction of the designs over the course of time for each group in order to examine the role of several design strategies described in the literature as central in procedural design. In the course of these analyses, we developed a generic way (design template) of comparing the final designs of designers in different paradigms. Using this template, we analyzed the designs in terms of their completeness for different views at different levels of abstraction. Our analyses of procedural and OO designers-in terms of their cognitive activities, design strategies, and final designs-provide a detailed comparison between design paradigms in practice. A variety of descriptive results are discussed in terms of positive transfer, interference, and implications for design training. Findings are also discussed in terms of the relation between tasks and design paradigms.
 
Mathematics relies on visual forms of communication and is thus largely inaccessible to people who cannot communicate in this manner because of visual disabilities. This article outlines the Mathtalk project, which addressed this problem by using computers to produce multimodal renderings of mathematical information. This example is unusual in that it is essential to use multiple modalities because of the nature and the difficulty of the application. In addition, the emphasis is on nonvisual (and hence novel) modalities. Crucial to designing a usable auditory interface to algebra notation is an understanding of the differences between visual and listening reading, particularly those aspects that make the former active and the latter passive. A discussion of these differences yields the twin themes of compensation for lack of external memory and provision of control over information flow. These themes were addressed by: the introduction of prosody to convey algebraic structure in synthetically spoken expressions; the provision of structure-based browsing functions; and the use of a prosody-based musical glance based on algebra earcons.
 
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.
 
Kieras and Polson (1985) proposed an approach for making quantitative predictions on ease of learning and ease of use of a system, based on a production system version of the goals, operators, methods, and selection rules (GOMS) model of Card, Moran, and Newell (1983). This article describes the principles for constructing such models and obtaining predictions of learning and execution time. A production rule model for a simulated text editor is described in detail and is compared to experimental data on learning and performance. The model accounted well for both learning and execution time and for the details of the increase in speed with practice. The relationship between the performance model and the Keystroke-Level Model of Card et al. (1983) is discussed. The results provide strong support for the original proposal that production rule models can make quantitative predictions for both ease of learning and ease of use.
 
We describe the development of a computational cognitive model that explains navigation behavior on the World Wide Web. The model, called SNIF-ACT (Scent-based Navigation and Information Foraging in the ACT cognitive architecture), is motivated by Information Foraging Theory (IFT), which quantifies the perceived relevance of a Web link to a user's goal by a spreading activation mechanism. The model assumes that users evaluate links on a Web page sequentially and decide to click on a link or to go back to the previous page by a Bayesian satisficing model (BSM) that adaptively evaluates and selects actions based on a combination of previous and current assessments of the relevance of link texts to information goals. SNIF-ACT 1.0 utilizes the measure of utility, called information scent, derived from IFT to predict rankings of links on different Web pages. The model was tested against a detailed set of protocol data collected from 8 participants as they engaged in two information-seeking tasks using the World Wide Web. The model provided a good match to participants' link selections. In SNIF-ACT 2.0, we included the adaptive link selection mechanism from the BSM that sequentially evaluates links on a Web page. The mechanism allowed the model to dynamically build up the aspiration levels of actions in a satisficing process (e.g., to follow a link or leave a Web site) as it sequential assessed link texts on a Web page. The dynamic mechanism provides an integrated account of how and when users decide to click on a link or leave a page based on the sequential, ongoing experiences with the link context on current and previous Web pages. SNIF-ACT 2.0 was validated on a data set obtained from 74 subjects. Monte Carlo simulations of the model showed that SNIF-ACT 2.0 provided better fits to human data than SNIF-ACT 1.0 and a Position model that used position of links on a Web page to decide which link to select. We conclude that the combination of the IFT and the BSM provides a good description of user-Web interaction. Practical implications of the model are discussed.
 
The ACT-R system is a general system for modeling a wide range of higher level cognitive processes. Recently, it has been embellished with a theory of how its higher level processes interact with a visual interface. This includes a theory of how visual attention can move across the screen, encoding information into a form that can be processed by ACT-R. This system is applied to modeling several classic phenomena in the literature that depend on the speed and selectivity with which visual attention can move across a visual display. ACT-R is capable of interacting with the same computer screens that subjects do and, as such, is well suited to provide a model for tasks involving human-computer interaction. In this article, we discuss a demonstration of ACT-R's application to menu selection and show that the ACT-R theory makes unique predictions, without estimating any parameters, about the time to search a menu. These predictions are confirmed.
 
Many psychological studies have shown that when we act, and especially when we interact, we consciously and unconsciously attend to context of many types. Sensors can pick up some but not all context that is acquired through our senses. Some context is lost, some is added, and captured context is presented in new ways. Digital aggregators and interpreters do not aggregate and interpret the same way we do. Missing or altered context disrupts our processing of information in ways that we may not recognize. To address the disruption we may use additional sensors to capture and deliver some of the missing context. Learning to handle these new conduits is then a further source of disruption, and on it can go. With greater knowledge of context, we can work and interact more efficiently, assuming that we can learn to take advantage of the information without being overwhelmed. However, converting contextual information to a digital format changes it in specific ways. Transient information becomes more permanent, local information is made available globally, and information that once spread slowly can spread much more quickly. The information can enable us to work more efficiently, but these changes in its nature have profound indirect effects. The potential loss of privacy is widely discussed, but other effects may be more significant. In particular, the loss of confinement and transience of information creates an environment that is fundamentally unnatural, in conflict with the one we evolved to live in.
 
Air traffic controllers participated in high-fidelity simulations of en route air traffic, either singly or with a second team member. The observed stream of time-stamped behaviors and communication events was analyzed using the Pathfinder scaling algorithm, which provides a directional graph of the latent structure in the data. The graphs were found to be similar across levels of traffic complexity, and the triggers for frequently co-occurring activities were equivalent for the individuals and the teams. This suggests that numerous aspects of air traffic control performance are robust and transcend some powerful situational variables. The implications for interface design and automation are discussed.
 
An example screen of the GUI of IFM 
Example of presentation of alternative actions 
Example of presentation of the explanation of advice 
This article is about a graphical user interface (GUI) that provides intelligent help to users. The GUI is called IFM (Intelligent File Manipulator). IFM monitors users while they work; if a user has made a mistake with respect to his or her hypothesized intentions, then IFM intervenes automatically and offers advice. IFM has two underlying reasoning mechanisms: One is based on an adaptation of a cognitive theory called human plausible reasoning and the other one performs goal recognition based on the effects of users' commands. The requirement analysis of the system has been based on an empirical study that was conducted involving real users of a standard file manipulation program like the Windows Explorer; this analysis revealed a need for intelligent help. Finally, IFM has been evaluated in comparison with a standard file manipulation GUI and in comparison with human experts acting as consultants. The results of the evaluation showed that IFM can produce successfully advice that is helpful to users.
 
In this commentary we reflect on the articles in this special issue on computer-mediated communication (CMC) "about things." We do this from our perspective as researchers of the sociotechnical practices of developing, using, and evaluating information technologies for health care work. The relevance of the articles for a medical setting is evaluated, and we also indicate that the material embeddedness of CMC should be "unpacked." By focusing on the materiality of CMC in its working practice, we can see the otherwise invisible work that performs the ecology needed to "make a CMC work." Only when seeing these activities, and when realizing the risks of possible miscommunications, can we assess the desirability and feasibility of (telemedicine) CMC projects.
 
A technique based on two heuristic rules for inferring expertise is demonstrated by inferring user expertise in word-processing tasks. The heuristic rules were translated into practice by examining command frequencies and requests for on-line help from the 12 participants in the study who were engaged in personal word-processing tasks. These variables were found to be related to word-processing expertise. A scoring rule derived from these variables ranged from 71% to 87% correct in predicting the expertise of the user. The application of this technique to adaptive interfaces that incorporate estimates of user expertise is discussed.
 
In this descriptive and exploratory study, 32 users type help requests to what they believe is a computerized advisor. In fact, the advisor is a human mimicking realistic levels of intelligence and knowledge that can be expected from a computerized advisor. Results show that users request help with a very simple and restricted language that is characteristic of language generated under real-time production constraints and of child language. Moreover, users' utterances are frequently ungrammatical. It is hypothesized that these features arise from factors intrinsic to typed advisory situations: Users are performing a primary task under real-time constraints, and typing help requests is a secondary task. On the other hand, users refer to objects and events with very precise descriptions instead of faster-to-type pronouns; they produce very few ellipses and deictic expressions. Future research should elucidate whether shared context between users and computerized advisors needs to be richer than created in this study to sustain the use of expressions whose interpretations depend on context. The tuning of natural language interfaces to the features observed in this study may increase the usefulness of natural language interfaces to advisory systems. The presented methodology is a promising tool for further studies of these factors on users' language.
 
The design of complex social systems, such as online communities, requires the consideration of many parameters, a practice at odds with social science research that focuses on the effects of a small set of variables. In this article, we show how synthesizing insights from multiple, narrowly focused social science theories in an agent-based model helps us understand factors that lead to the success of online communities. The agent-based model combines insights from theories related to collective effort, information overload, social identity, and interpersonal attraction to predict motivations for online community participation. We conducted virtual experiments to develop hypotheses around three design decisions about how to orchestrate an online community—topical breadth, message volume, and discussion moderation—and the trade-offs involved in making these decisions. The simulation experiments suggest that broad topics and high message volume can lead to higher member commitment. Personalized moderation outperforms other types of moderation in increasing members' commitment and contribution, especially in topically broad communities and those with high message volume. In comparison, community-level moderation increases commitment but not contribution, and only in topically narrow communities. These simulation results suggest a critical trade-off between informational and relational benefits. This research illustrates that there are many interactions among the design decisions that are important to consider; the particulars of the community's goals often determine the effectiveness of some decisions. It also demonstrates the value of agent-based modeling in synthesizing simple social science theories to describe and prescribe behaviors in a complex system, generating novel insights that inform the design of online communities.
 
A multimodal presentation planning mechanism must take into consideration the structure of the discourse and the constraints imposed by discourse relations. This requires that different processes that perform multimodal presentation planning be able to communicate with each other. In this article, we introduce a multiagent architecture based on the blackboard system that satisfies this requirement. In addition, we describe a constraint propagation mechanism that transfers plan constraints from one level of the presentation planning process to the next, and we discuss the cooperation and negotiation processes between modality-specific agents in a prototype system that implements the multiagent planning mechanism.
 
The current study was concerned with the basic question of how to overcome users' disorientation when navigating through hierarchical menus in small-screen technical devices, as for example mobile phones. In these devices, menu functions are typically organized in a tree structure. Two different navigation aids were implemented into a computer simulation of a real mobile phone (Siemens S45 ®). The interface of the first navigation aid (the "category" aid) showed the name of the current category as well as a list of its contents. The interface of the other navigation aid (the "tree" aid) was identical to the first except that it also showed the parents and parent-parents of the current of the category and it indented the subcategories to emphasize the hierarchical structure. For the study, 16 younger (23-28 years) and 16 older adults (46-60 years) had to solve 9 common phone tasks twice consecutively to measure learnability. To gain further insight into user characteristics modulating navigation performance and possibly interacting with the utility of the navigation aids, we assessed users' verbal memory and spatial abilities. Dependent variables were task effectiveness (number of tasks solved) and efficiency (time on task, number of returns in menu hierarchy, and returns to the top). The results reveal a consistent and significant advantage of the tree aid for both age groups, an advantage that was larger for users with lower spatial abilities and older adults. In general, older adults had lower verbal memory and spatial abilities, which were found to account for their lower navigation performance. We assume that the strong advantage of the tree aid is due to the spatial information on the menu structure, which thus conveys survey knowledge. This allows users to form an adequate mental representation of the menu. It is recommended to add a navigation aid providing survey knowledge into the displays of small-screen devices to achieve better overall performance.
 
This study set out to delineate the Scandinavian Approach to the development of computer-based systems. We aimed to help derive new ideas for human-oriented technology design in other countries. The study is based on the relevant literature, scientific contacts, and two field trips, and covers work in Denmark, Norway, and Sweden. The study focuses on methodological questions and their theoretical foundations, on explicit strategies for social implementation, and on innovative design illustrated by reference to concrete projects. Though it makes no claim to present a sociopolitical analysis of Scandinavian technology design, the sociocultural background is given due consideration. There is no general agreement among Scandinavians as to whether or not there is a well-defined Scandinavian Approach. We have come to identify such an approach in certain common features shared by the different schools of thought. These include efforts toward humanization and democratization as overriding design goals, in keeping with the aim of building an egalitarian society.
 
The problem-solving abilities of casual users were compared to experienced users in a computer setting. It was hypothesized that casual users would benefit from reduced consistency with other applications. Experience was gauged with a questionnaire and empirical measures. Four interfaces were developed with varying degrees of similarity to Web browsers. Using a Web browser as a source problem, participants were tested with two of the experimental interfaces. The data indicated that the accuracy of casual users was equivalent across consistent and inconsistent interfaces but that the consistent interfaces had significantly higher latencies. The primary conclusions of the study are that performance for casual users is improved by superficially inconsistent interfaces and that their performance is equivalent to experienced users when a true analogue is present. Commonalities with familiar elements may be a hindrance.
 
Analytical usability evaluation methods (UEMs) can complement empirical evaluation of systems: for example, they can often be used earlier in design and can provide accounts of why users might experience difficulties, as well as what those difficulties are. However, their properties and value are only partially understood. One way to improve our understanding is by detailed comparisons using a single interface or system as a target for evaluation, but we need to look deeper than simple problem counts: we need to consider what kinds of accounts each UEM offers, and why. Here, we report on a detailed comparison of eight analytical UEMs. These eight methods were applied to a robotic arm interface, and the findings were systematically compared against video data of the arm in use. The usability issues that were identified could be grouped into five categories: system design, user misconceptions, conceptual fit between user and system, physical issues, and contextual ones. Other possible categories such as user experience did not emerge in this particular study. With the exception of Heuristic Evaluation, which supported a range of insights, each analytical method was found to focus attention on just one or two categories of issues. Two of the three “home-grown” methods (Evaluating Multimodal Usability and Concept-based Analysis of Surface and Structural Misfits) were found to occupy particular niches in the space, whereas the third (Programmable User Modeling) did not. This approach has identified commonalities and contrasts between methods and provided accounts of why a particular method yielded the insights it did. Rather than considering measures such as problem count or thoroughness, this approach has yielded insights into the scope of each method.
 
Animated demonstrations display the execution of interface procedures. They appear to be a natural and fast way for users to learn direct-manipulation interfaces by watching. To assess their effectiveness for users learning HyperCardTM, we compared carefully matched animated demonstrations, procedural textual instructions, and demonstrations combined with spoken procedural text. During training, demonstration users were faster and more accurate than text-only users. Without the instructions, 7 days later, text-only users were faster and as accurate as demonstration users in recalling and performing identical and similar tasks without the instructions. Surprisingly, users of the combined demonstrations with spoken text closely mirrored the results of the demonstration-only users. The poor retention and transfer for the demonstration users appeared to be due to mimicry of the demonstrated procedures. Even with accompanying spoken text, the simplicity of using animated demonstrations may encourage superficial processing and disregard for the procedural text.
 
Algorithm animation has a growing role in computer-aided algorithm design, documentation, and debugging, because interactive graphics is a richer channel than text for communication. Most animation is currently done laboriously by hand, and it often has the character of canned demonstrations with restricted user interaction. Animus is a system that allows for easy construction of an animation with minimal concern for lower-level graphics programming. Constraints are used to describe the appearance and structure of a picture as well as how those pictures evolve in time. The implementation and support of temporal constraints are substantive extensions to previous constraint languages that had only allowed for the specification of a static state. Use of the Animus system is demonstrated in the creation of animations of dynamic mechanical and electrical circuit simulations, sorting algorithms, problems in operating systems, and geometric curve drawing algorithms.
 
We introduce and explore the notion of "intentionally enriched awareness." Intentional enrichment refers to the process of actively engaging users in the awareness process by enabling them to express intentions. We explore this concept designing and evaluating the AnyBiff system, which allows users to freely create, share, and use a variety of biff applications. Biffs are simple representation of predefined activities. Users can select biffs to indicate that they are engaged in an activity. AnyBiff was deployed in two different organizations as part of a user-centered design process. We report on the results of the trial, which allowed us to gain insights into the potential of the AnyBiff prototype and the underlying biff concept to implement intentionally enriched awareness. Our findings show that intentional disclosure mechanisms in the form of biffs were successfully used in both fields of application. Users actively engaged in the design of a large variety of biffs and explored many different uses of the concept. The study revealed a whole host of issues with regard to intentionally enriched awareness, which give valuable insight into the conception and design of future applications in this area.
 
Visual approaches for conducting research during the design process often give voice to people and ideas that might otherwise remain obscured. Recent and increasing interest in visual research techniques has coincided with technological advances such as camera phones and visually oriented mobile applications. As a result of this close association between digital technologies and image-based research techniques, there are multiple opportunities and challenges within human–computer interaction (HCI) design practice to employ these strategies to improve user experiences. This article provides an overview of current visual approaches to research highlighting the role technology has played in facilitating and inspiring these techniques. A series of case studies are presented that provide a basis for understanding a breadth of visual approaches in HCI design practices as well as serve as a point of entry to a critical and reflective discussion about the use of these approaches in different circumstances. Based on these reflections, three value statements are offered as a means to encourage the use of these visual approaches more broadly and critically in HCI design studies.
 
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 article presents a use-oriented analysis of a graphical argumentation notation known as QOC (Questions, Options, and Criteria). 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 on 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.
 
Documenting argumentation (i.e., design rationale) has great potential for serving design. Despite this potential benefit, our analysis of Horst Rittel's and Donald Schön's design theories and of our own experience has shown that there are the following fundamental obstacles to the effective documentation and use of design rationale: (a) A rationale representation scheme must be found that organizes information according to its relevance to the task at hand; (b) computer support is needed to reduce the burden of recording and using rationale; (c) argumentative and constructive design activities must be linked explicitly by integrated design environments; (d) design rationale must be reusable. In this article, we present the evolution of our conceptual frameworks and systems toward integrated design environments; describe a prototype of an integrated design environment, including its underlying architecture; and discuss some current and future work on extending it.
 
The growing interest in multimodal interface design is inspired in large part by the goals of supporting more transparent, flexible, efficient, and powerfully expressive means of human-computer interaction than in the past. Multimodal interfaces are expected to support a wider range of diverse applications, be usable by a broader spectrum of the average population, and function more reliably under realistic and challenging usage conditions. In this article, we summarize the emerging architectural approaches for interpreting speech and pen-based gestural input in a robust manner-including early and late fusion approaches, and the new hybrid symbolic-statistical approach. We also describe a diverse collection of state-of-the-art multimodal systems that process users' spoken and gestural input. These applications range from map-based and virtual reality systems for engaging in simulations and training, to field medic systems for mobile use in noisy environments, to web-based transactions and standard text-editing applications that will reshape daily computing and have a significant commercial impact. To realize successful multimodal systems of the future, many key research challenges remain to be addressed. Among these challenges are the development of cognitive theories to guide multimodal system design, and the development of effective natural language processing, dialogue processing, and error-handling techniques. In addition, new multimodal systems will be needed that can function more robustly and adaptively, and with support for collaborative multiperson use. Before this new class of systems can proliferate, toolkits also will be needed to promote software development for both simulated and functioning systems.
 
Top-cited authors
Marc Hassenzahl
  • Universität Siegen
Chaomei Chen
  • College of Computing and Informatics, Drexel University
Roy Rada
  • University of Maryland, Baltimore County
Jesse Fox
  • The Ohio State University
Sun Joo-Grace Ahn
  • University of Georgia