Showing papers in "ACM Transactions on Computer-Human Interaction in 2005"

Establishing and maintaining long-term human-computer relationships

Abstract: This research investigates the meaning of “human-computer relationship” and presents techniques for constructing, maintaining, and evaluating such relationships, based on research in social psychology, sociolinguistics, communication and other social sciences Contexts in which relationships are particularly important are described, together with specific benefits (like trust) and task outcomes (like improved learning) known to be associated with relationship quality We especially consider the problem of designing for long-term interaction, and define relational agents as computational artifacts designed to establish and maintain long-term social-emotional relationships with their users We construct the first such agent, and evaluate it in a controlled experiment with 101 users who were asked to interact daily with an exercise adoption system for a month Compared to an equivalent task-oriented agent without any deliberate social-emotional or relationship-building skills, the relational agent was respected more, liked more, and trusted more, even after four weeks of interaction Additionally, users expressed a significantly greater desire to continue working with the relational agent after the termination of the study We conclude by discussing future directions for this research together with ethical and other ramifications of this work for HCI designers

A multilevel analysis of sociability, usability, and community dynamics in an online health community

Abstract: The aim of this research is to develop an in-depth understanding of the dynamics of online group interaction and the relationship between the participation in an online community and an individual's off-line life. The 2h-year study of a thriving online health support community (Bob's ACL WWWBoard) used a broad fieldwork approach, guided by the ethnographic research techniques of observation, interviewing, and archival research in combination with analysis of the group's dynamics during a one-week period. Research tools from the social sciences were used to develop a thick, rich description of the group. The significant findings of this study include: dependable and reliable technology is more important than state-of-the-art technology in this community; strong community development exists despite little differentiation of the community space provided by the software; members reported that participation in the community positively influenced their offline lives; strong group norms of support and reciprocity made externally-driven governance unnecessary; tools used to assess group dynamics in face-to-face groups provide meaningful information about online group dynamics; and, membership patterns in the community and strong subgroups actively contributed to the community's stability and vitality.

Making by making strange: Defamiliarization and the design of domestic technologies

Abstract: This article argues that because the home is so familiar, it is necessary to make it strange, or defamiliarize it, in order to open its design space. Critical approaches to technology design are of both practical and social importance in the home. Home appliances are loaded with cultural associations such as the gendered division of domestic labor that are easy to overlook. Further, homes are not the same everywhere---even within a country. Peoples' aspirations and desires differ greatly across and between cultures. The target of western domestic technology design is often not the user, but the consumer. Web refrigerators that create shopping lists, garbage cans that let advertisers know what is thrown away, cabinets that monitor their contents and order more when supplies are low are central to current images of the wireless, digital home of the future. Drawing from our research in the United States, the United Kingdom, and Asia, we provide three different narratives of defamiliarization. A historical reading of American kitchens provides a lens with which to scrutinize new technologies of domesticity, an ethnographic account of an extended social unit in England problematizes taken-for-granted domestic technologies, and a comparative ethnography of the role of information and communication technologies in the daily lives of urban Asia's middle classes reveals the ways in which new technologies can be captured and domesticated in unexpected ways. In the final section of the article, we build on these moments of defamiliarization to suggest a broad set of challenges and strategies for design in the home.

Predicting human interruptibility with sensors

Abstract: A person seeking another person's attention is normally able to quickly assess how interruptible the other person currently is. Such assessments allow behavior that we consider natural, socially appropriate, or simply polite. This is in sharp contrast to current computer and communication systems, which are largely unaware of the social situations surrounding their usage and the impact that their actions have on these situations. If systems could model human interruptibility, they could use this information to negotiate interruptions at appropriate times, thus improving human computer interaction.This article presents a series of studies that quantitatively demonstrate that simple sensors can support the construction of models that estimate human interruptibility as well as people do. These models can be constructed without using complex sensors, such as vision-based techniques, and therefore their use in everyday office environments is both practical and affordable. Although currently based on a demographically limited sample, our results indicate a substantial opportunity for future research to validate these results over larger groups of office workers. Our results also motivate the development of systems that use these models to negotiate interruptions at socially appropriate times.

Social matching: A framework and research agenda

Abstract: Social matching systems bring people together in both physical and online spaces. They have the potential to increase social interaction and foster collaboration. However, social matching systems lack a clear intellectual foundation: the nature of the design space, the key research challenges, and the roster of appropriate methods are all ill-defined. This article begins to remedy the situation. It clarifies the scope of social matching systems by distinguishing them from other recommender systems and related systems and techniques. It identifies a set of issues that characterize the design space of social matching systems and shows how existing systems explore different points within the design space. It also reviews selected social science results that can provide input into system design. Most important, the article presents a research agenda organized around a set of claims. The claims embody our understanding of what issues are most important to investigate, our beliefs about what is most likely to be true, and our suggestions of specific research directions to pursue.

Token+constraint systems for tangible interaction with digital information

Abstract: We identify and present a major interaction approach for tangible user interfaces based upon systems of tokens and constraints. In these interfaces, tokens are discrete physical objects which represent digital information. Constraints are confining regions that are mapped to digital operations. These are frequently embodied as structures that mechanically channel how tokens can be manipulated, often limiting their movement to a single degree of freedom. Placing and manipulating tokens within systems of constraints can be used to invoke and control a variety of computational interpretations.We discuss the properties of the token+constraint approach; consider strengths that distinguish them from other interface approaches; and illustrate the concept with eleven past and recent supporting systems. We present some of the conceptual background supporting these interfaces, and consider them in terms of Bellotti et al.'s [2002] five questions for sensing-based interaction. We believe this discussion supports token+constraint systems as a powerful and promising approach for sensing-based interaction.

Socio-technical environments supporting people with cognitive disabilities using public transportation

Abstract: Public transportation systems are among the most ubiquitous and complex large-scale systems found in modern society. For those unable to drive such as people with cognitive disabilities, these systems are essential gateways for participation in community activities, socialization, and independence. To understand the magnitude and scope of this national problem, we highlight deficiencies identified in an international study by the Transportation Research Board of the National Research Council and present specific cognitive barriers identified in empirical studies of transportation systems in several U.S. cities.An interdisciplinary team of HCI researchers, urban transportation planners, commercial technologists, and assistive care specialists are now collaborating on the Mobility-for-All project to create architectures and prototypes that support those with cognitive disabilities and their caregivers. We have grounded our research and design efforts using a distributed cognition framework. We have derived requirements for our designs by analyzing “how things are” for individuals with cognitive disabilities who learn and use public transportation systems. We present a socio-technical architecture that has three components: a) a personal travel assistant that uses real-time Global Positioning Systems data from the bus fleet to deliver just-in-time prompts; b) a mobile prompting client and a prompting script configuration tool for caregivers; and c) a monitoring system that collects real-time task status from the mobile client and alerts the support community of potential problems. We then describe a phased community-centered assessment approach that begins at the design stage and continues to be integrated throughout the project.This research has broad implications for designing more human-centered transportation systems that are universally accessible for other disenfranchised communities such as the elderly or nonnative speaker. This project presents an “in-the-world” research opportunity that challenges our understanding about mobile human computer interactions with ubiquitous, context-aware computing architectures in noisy, uncontrolled environments; personalization and user modeling techniques; and the design of universally accessible interfaces for complex systems through participatory design processes.This article provides both a near-term vision and an architecture for transportation systems that are socially inclusive, technologically appealing, and easier for everyone to use.

High-cost banner blindness: Ads increase perceived workload, hinder visual search, and are forgotten

Abstract: The seeming contradiction between “banner blindness” and Web users' complaints about distracting advertisements motivates a pair of experiments into the effect of banner ads on visual search. Experiment 1 measures perceived cognitive workload and search times for short words with two banners on the screen. Four kinds of banners were examined: (1) animated commercial, (2) static commercial, (3) cyan with flashing text, and (4) blank. Using NASA's Task Load Index, participants report increased workload under flashing text banners. Experiment 2 investigates search through news headlines at two levels of difficulty: exact matches and matches requiring semantic interpretation. Results show both animated and static commercial banners decrease visual search speeds. Eye tracking data reveal people rarely look directly at banners. A post hoc memory test confirms low banner recall and, surprisingly, that animated banners are more difficult to remember than static look-alikes. Results have implications for cognitive modeling and Web design.

Fitts' law and expanding targets: Experimental studies and designs for user interfaces

Abstract: Recently, there has been renewed interest in techniques for facilitating the selection of user interface widgets or other on-screen targets with a pointing device. We report research into using target expansion for facilitating selection. Widgets that expand or grow in response to the user's focus of attention allow for a reduced initial size which can help optimize screen space use and may be easier to select than targets that do not expand. However, selection performance could plausibly suffer from a decreased initial widget size. We describe an experiment in which users select a single, isolated target button that expands just before it is selected. Our results show that users benefit from target expansion even if the target only begins expanding after 90p of the distance to the target has been travelled. Furthermore, our results suggest that, for sufficiently large ID values, users are able to take approximately full advantage of the expanded target size. For interfaces with multiple expanding widgets, however, subtle problems arise due to the collisions or overlap that may occur between adjacent expanding widgets. We give a detailed examination of the issues involved in both untiled and tiled multiple expanding targets and present various design strategies for improving their performance.

Expected, sensed, and desired: A framework for designing sensing-based interaction

Abstract: Movements of interfaces can be analyzed in terms of whether they are expected, sensed, and desired. Expected movements are those that users naturally perform; sensed are those that can be measured by a computer; and desired movements are those that are required by a given application. We show how a systematic comparison of expected, sensed, and desired movements, especially with regard to how they do not precisely overlap, can reveal potential problems with an interface and also inspire new features. We describe how this approach has been applied to the design of three interfaces: pointing flashlights at walls and posters in order to play sounds; the Augurscope II, a mobile augmented reality interface for outdoors; and the Drift Table, an item of furniture that uses load sensing to control the display of aerial photographs. We propose that this approach can help to build a bridge between the analytic and inspirational approaches to design and can help designers meet the challenges raised by a diversification of sensing technologies and interface forms, increased mobility, and an emerging focus on technologies for everyday life.

The language of privacy: Learning from video media space analysis and design

Abstract: Video media spaces are an excellent crucible for the study of privacy. Their design affords opportunities for misuse, prompts ethical questions, and engenders grave concerns from both users and nonusers. Despite considerable discussion of the privacy problems uncovered in prior work, questions remain as to how to design a privacy-preserving video media space and how to evaluate its effect on privacy. The problem is more deeply rooted than this, however. Privacy is an enormous concept from which a large vocabulary of terms emerges. Disambiguating the meanings of and relationships between these terms facilitates understanding of the link between privacy and design. In this article, we draw from resources in environmental psychology and computer-supported cooperative work (CSCW) to build a broadly and deeply rooted vocabulary for privacy. We relate the vocabulary back to the real and hard problem of designing privacy-preserving video media spaces. In doing so, we facilitate analysis of the privacy-design relationship.

An investigation into the effects of Text-To-Speech voice and 3D avatars on the perception of presence and flow of live help in electronic commerce

Abstract: Expansion and growth of online shopping has led many companies to provide real-time communications on their Web sites to facilitate human-to-human interaction between service representatives and customers. The current study analyzes the interface design of such Live Help functions. More specifically, it attempts to understand whether or not the implementation of Text-To-Speech (TTS) voice communication and 3D avatars in the user interface of Live Help affects consumers' views of their own interactions with a service person.A laboratory experiment was designed to empirically test the hypotheses that TTS voice communication and 3D avatars can significantly affect consumers' perceptions of presence and flow. A 2a3 full factorial design was used (assessing three options for the use of voice and text, and two options for the use of avatars). The results of the experiment demonstrate that the presence of TTS voice significantly increases consumers' perceptions of flow (a construct depicting a user's interaction with a computer as playful and exploratory), while 3D avatars enhance consumers' feelings of telepresence (a user's experience of seeming to be present in a remote environment by means of a communication medium). These findings offer practitioners guidelines on how to improve interface designs for real-time human-to-human communications on electronic commerce Web sites.

Designing mediation for context-aware applications

Abstract: Many context-aware services make the assumption that the context they use is completely accurate. However, in reality, both sensed and interpreted context is often ambiguous. A challenge facing the development of realistic and deployable context-aware services, therefore, is the ability to handle ambiguous context. Although some of this ambiguity may be resolved using automatic techniques, we argue that correct handling of ambiguous context will often need to involve the user. We use the term mediation to refer to the dialogue that ensues between the user and the system. In this article, we describe an architecture that supports the building of context-aware services that assume context is ambiguous and allows for mediation of ambiguity by mobile users in aware environments. We present design guidelines that arise from supporting mediation over space and time, issues not present in the graphical user interface domain where mediation has typically been used in the past. We illustrate the use of our architecture and evaluate it through an example context-aware application, a word predictor system.

Foreground and background interaction with sensor-enhanced mobile devices

Abstract: Building on Buxton's foreground/background model, we discuss the importance of explicitly considering both foreground interaction and background interaction, as well as transitions between foreground and background, in the design and implementation of sensing techniques for sensor-enhanced mobile devices. Our view is that the foreground concerns deliberate user activity where the user is attending to the device, while the background is the realm of inattention or split attention, using naturally occurring user activity as an input that allows the device to infer or anticipate user needs. The five questions for sensing systems of Bellotti et al. [2002] proposed as a framework for this special issue, primarily address the foreground, but neglect critical issues with background sensing. To support our perspective, we discuss a variety of foreground and background sensing techniques that we have implemented for sensor-enhanced mobile devices, such as powering on the device when the user picks it up, sensing when the user is holding the device to his ear, automatically switching between portrait and landscape display orientations depending on how the user is holding the device, and scrolling the display using tilt. We also contribute system architecture issues, such as using the foreground/background model to handle cross-talk between multiple sensor-based interaction techniques, and theoretical perspectives, such as a classification of recognition errors based on explicitly considering transitions between the foreground and background. Based on our experiences, we propose design issues and lessons learned for foreground/background sensing systems.

Designing and evaluating kalas: A social navigation system for food recipes

Abstract: The idea of social navigation is to aid users to navigate information spaces through making the collective, aggregated, or individual actions of others visible and useful as a basis for making decisions on where to go next and what to choose. These social markers should also help in turning the navigation experience into a social and pleasurable one rather than the tedious, boring, frustrating, and sometimes even scary experience of a lonely traveler. To evaluate whether it is possible to design for social navigation, we built the food recipe system Kalas. It includes several different forms of aggregated trails of user actions and means of communication between users: recommender system functionality (recommendations computed from others' choices), real-time broadcasting of concurrent user activity in the interface, possibilities to comment and vote on recipes, the number of downloads per recipe, and chatting facilities. Recipe author was also included in the recipe description.Kalas was tried with 302 users during six months, and 73 of the users answered a final questionnaire. The overall impression was that users liked and acted on aggregated trails and navigated differently because of them. 18% of the selected recipes came from the list of recommended recipes. About half of the 73 users understood that recommendations were computed from their own and others actions, while the rest had not reflected upon it or had erroneous beliefs. Interestingly, both groups selected a large proportion of their recipes from the recommendations.Unfortunately, there were not enough users to populate the space at every occasion, and thus both chatting and following other users moving in the space was for the most part not possible, but when possible, users move to the space where most other users could be found. Of the other social textures, users themselves claimed to be most influenced by other users' comments attached to the recipes and less by recipe author or number of downloads. Users are more positive to the possibility of expressing themselves in terms of comments and voting than seeing the comments and votes of others.It was noted that users did not pick more recommended recipes towards the end of the study period when the accuracy of recommendations should have been higher. More or less from the start, they picked recommended recipes and went on doing so throughout the whole period.

A probabilistic approach to modeling two-dimensional pointing

Abstract: We investigate and model two-dimensional pointing where the target distance and size vary as does the angle of movement. We first study the spread of hits in a rapid approximate pointing task at varied distances and movement angles. Consistent with the literature, our results show that the spread of hits along the movement direction deviate more than the spread of hits in the direction perpendicular to movement, and both spreads increase with distance. Based on the distribution of this spread of hits, we propose and validate a new probabilistic model that describes two-dimensional pointing. Unlike previous models, our model accounts for more variables of two-dimensional pointing and can be generalized to any target shape, size, orientation, location, and dimension. In contrast to previous work, which suggests that target height has minimal impact on performance when it is larger than the width, our results show that, even when height is greater than width, it can significantly impact movement time.

Managing availability: Supporting lightweight negotiations to handle interruptions

Abstract: Interruptions are a central aspect of working life. The prevalence of remote co-workers and the use of mobile technology mean that interruptions are more prevalent, and workers have to learn to manage availability. To understand general issues in availability management, we carried out a naturalistic study of how interruptions are handled in face-to-face situations. We found that availability management requires negotiation, that it is also highly dependent on awareness about the availability of others, and that it demands cognitive effort to shift attention to the interruption. On the basis of these observations, we developed a technology, named. The Negotiator, that embodies three main design requirements: (a) support for negotiation, (b) contextual information about when a recipient is available for a call, (c) lightweightness to reduce attention overhead. We carried out an experimental study of interruption management using this technology. The interface satisfied the original design requirements, that is, people, were able to use it effectively to negotiate times to talk, while successfully carrying out an intellectually demanding activity. Contrary to our expectations, however, people preferred to take responsibility for returning calls rather than delegating them, and they preferred to schedule calls as soon as possible rather than deferring them. We suggest that there are social reasons why people do this. They feel a social obligation to return calls as soon as possible so as not to inconvenience others and also to be responsible for making these calls themselves. They also take calls sooner to avoid having to remember future conversational commitments. We discuss the theoretical and technical implications of these findings.

Social empowerment and exclusion: A case study on digital libraries

Abstract: This article reports on work studying how technology can empower or exclude its users due to interactions between social context, system design, and implementation. The analysis is based around the introduction and use of digital libraries in four different settings, three clinical and one academic. Across the four settings, in-depth interview and focus group data was collected from 144 users and analyzed with reference to “communities of practice”. The four settings represent three different approaches to digital library implementation: making digital library resources available from existing computer systems in people's offices and the library (a traditional approach); making computer systems, and hence digital libraries, available in shared spaces (in this case, hospital wards); and employing information intermediaries to work with staff and library resources. These different approaches engendered different perceptions of the technology. The traditional approach produced perceptions of technology as being irrelevant for current needs and community practices. Making technology available within shared physical space but with poor design, support, and implementation procedures was widely perceived as a threat to current organizational structures. In contrast, technology implemented within the community which could adapt and change practices according to individual and group needs, supported by an information intermediary, was seen as empowering to both the community and the individual. We relate the findings to a discussion of evolutionary and revolutionary approaches to design and to the concept of communities of practice.

Benefits of merging command selection and direct manipulation

Abstract: Toolglass [Bier et al. 1993] demonstrated a two-handed command selection technique that combined command selection and direct manipulation. While empirical evaluations showed a speed advantage for ToolGlass, they did not examine the relative importance of two possible factors in its improved performance: (1) the use of two hands and (2) the merging of command selection and direct manipulation.We conducted a study comparing the relative benefits of three command selection techniques that merge command selection and direct manipulation: one two-handed technique, Toolglass, and two one-handed techniques, namely, control menus [Pook et al. 2000] and FlowMenu [Guimbretiere and Winograd 2000]. Participants performed sequences of operations that required both selecting a color and designating the endpoints of a line. Our results show that control menus and FlowMenu are significantly faster than Toolglass. Further analysis suggests that the merging of command selection and direct manipulation is the most important factor in the performance of all three techniques.

Putting computing in context: An infrastructure to support extensible context-enhanced collaborative applications

Abstract: Context-aware computing exposes a unique tension in how information about human context is modeled and used. On the one hand, approaches that use loosely structured information have been shown to be useful in situations where humans are the final consumers of contextual information; these approaches have found favor in many CSCW applications. On the other hand, more rigidly structured information supports machine interpretation and exchange; these approaches have been explored in the ubiquitous computing community. The system presented here, dubbed Intermezzo, represents an exploration of a space between these two extremes. Intermezzo combines a loose data structuring with a number of unique features designed to allow applications to embed specialized semantic interpretations of data into the infrastructure, allowing them to be reused by other applications. This approach can enable the construction of applications that can take advantage of rich, layered interpretations of context without requiring that they understand all aspects of that context. This approach is explored through the creation of two higher-level services that provide context-enhanced session management and context-enhanced access control.

Introduction to the special section on recommender systems

Abstract: Information overload is not a new phenomenon. Rich’s comment might well resonate almost 400 years later with the modern Internet surfer or email user. In specific areas of inquiry, the problem is even worse than that facing casual information users. For example, MEDLINE, the online archive of published articles in medicine, grows at a rate of almost 500,000 entries per year. In the face of such an onslaught, how can we find our way through the thicket of information and opportunities? In the early 1990’s, one approach that emerged was to think of navigation through a space of information or opportunities as a collective activity rather than an individual one. In the everyday world, researchers reasoned, the activities of others give us cues that we can interpret as to the ways in which we want to organize our activities. A path through the woods shows the routes that others have traveled before (and which might be useful to us); dog-eared books in the library may be more popular and more useful than pristine ones; and the relative levels of activity in public space help guide is towards interesting places. These ideas helped spark an interest in the ways in which computing systems might use information about peoples interests and activities to form recommendations that help other people navigate through complex information spaces or decisions. These are recommender systems. Recommender systems have now been an active topic of research for over 12 years. In the early 21st century, hundreds of researchers are working on some aspect of recommender systems, hundreds of papers have already been written, and hundreds of enterprises have deployed recommender systems on the Internet and beyond. Online stores, libraries, information archives and more have developed and deployed recommender systems in order to help connect an individual users’ activity to the broader patterns of social action that might help to make it more meaningful. While other forms of collaborative technology emerging from the research community are often used only sparingly, recommender systems have seen broad uptake and have been remarkably successful. From the earliest days, much of this research and many of the deployments have focused on the algorithms that underlie the recommender systems. Algorithmic research has been rich and successful, exploring dozens of linear algebra, statistical, and machine learning approaches to producing ever more accurate recommendations. The field continues to be rich, with dozens of new

Introduction to sensing-based interaction

Abstract: It can be argued that intelligence lies as much in the ability to sense the environment as in the ability to reason. Increasingly, the Moore’s law effect is not only giving us more processing power in computers, but also making sensors and related signal processing capabilities widely available for making computers more “active”. With various sensing capabilities, a computer can know the presence, gesture, facial expression, eye-gaze and physiological states of its user as well as its own states such as location, orientation, distance with other identities, and so forth. These capabilities have drawn increasing interest from the HCI field in using sensing information to make human computer interaction ever more effective. Sensing-based interaction is also at the core of, or synonymous with, many emerging or fast developing areas of human-computer interaction research, including pervasive, ubiquitous or context aware computing, intelligent environments, augmented reality interfaces, and tangible interfaces. Many new ideas, analyses, and prototypes are pushing the boundaries of what we believe is possible with, and what we think is important about, sensing-based interaction. However, serious challenges lie ahead when human-system interaction switches to implicit sensing, rather than explicit command-based input. How can sensing-initiated interaction be made appropriate to the user and the particular context? How can sensing-based interaction be helpful and active but not disruptive to the user? How does a system know that the user is addressing it and not other systems? How does the user know that the system is attending to her request? How does the system know what object the user’s command (e.g. save) relates to? How does the user know that the system understands and is

Voter-centered design: Toward a voter decision support system

Abstract: Electronic voting support systems should not focus only on ballot casting and recording. Instead, a user-centered perspective should be adopted for the design of a system that supports information gathering, organizing and sharing, deliberation, decision making, and voting. Relevant social science literature on political decision making and voting is used to develop requirements. A design concept is presented that supports extended information browsing using combined filtering from ballot materials and voter profiles. The system supports information sharing and participation in electronic dialogues. Voters may interweave information browsing, annotation, contextualized discussion, and ballot markup over extended time periods.