Browsing by Author "Gutwin, Carl"
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- ItemOpen AccessAdapting the Locales Framework for Heuristic Evaluation of Groupware(1999-08-11) Greenberg, Saul; Fitzpatrick, Geraldine; Gutwin, Carl; Kaplan, SimonHeuristic evaluation is a rapid, cheap and effective way for identifying usability problems in single user systems. However, current heuristics do not provide guidance for discovering problems specific to groupware usability. In this paper, we take the Locales Framework and restate it as heuristics appropriate for evaluating groupware. These are: 1) Provide locales; 2) Provide awareness within locales; 3) Allow individual views; 4) Allow people to manage and stay aware of their evolving interactions; 5) Provide a way to organize and relate locales to one another. To see if these new heuristics are useful in practise, we used them to inspect the interface of Teamwave Workplace, a commercial groupware product. We were successful at identifying the strengths of Teamwave as well as both major and minor interface problems.
- ItemMetadata onlyAdaptive forward error correction for real-time groupware(ACM, 2012) Dyck, Jeff; Gutwin, Carl; Makaroff, DwightReal-time distributed groupware sends several kinds of messages with varying quality-of-service requirements. However, standard network protocols do not provide the flexibility needed to support these different requirements (either providing too much reliability or too little), leading to poor performance on real-world networks. To address this problem, we investigated the use of an application-level networking technique called adaptive forward error correction (AFEC) for real-time groupware. AFEC can maintain a predefined level of reliability while avoiding the overhead of packet acknowledgement or retransmission. We analysed the requirements of typical real-time groupware systems and developed an AFEC technique to meet these needs. We tested the new technique in an experiment that measured message reliability and latency using TCP, plain UDP, UDP with non-adaptive FEC, and UDP with our AFEC scheme, under several simulated network conditions. Our results show that for awareness messages that can tolerate some loss, FEC approaches keep latency at nearly the plain-UDP level while dramatically improving reliability. In addition, adaptive FEC is the only technique that can maintain a specified level of reliability and also minimize delay as network conditions change. Our study shows that groupware AFEC can be a useful tool for improving the real-world performance and usability of real-time groupware.
- ItemMetadata onlyAnalysis and comparison of target assistance techniques for relative ray-cast pointing(Elsevier, 2013) Bateman, Scott; Mandryk, Regan L.; Gutwin, Carl; Xiao, RobertPointing at displays from a distance is becoming a common method of interacting with computer applications and entertainment systems, using devices such as the Wii Remote, the PlayStation Move controller, or the Microsoft Kinect. These systems often implement relative forms of ray-cast pointing, in which the user simply points a hand-held input device towards targets on the screen. Ray-casting interaction is easy for novices to learn and understand, but this technique often suffers from accuracy problems: for example, hand jitter, arm fatigue, calibration drift, or lack of skill can all reduce people’s ability to acquire and select on-screen targets. In this paper, we analyse and evaluate the idea of target assistance as a way to address the accuracy problems of ray-cast pointing. Although several assistance schemes have been proposed for mouse-based pointing, these ideas have not been tested in distant-pointing settings, and there is little knowledge available to guide design in this increasingly common interaction scenario. To establish this basic design knowledge, we carried out four studies of relative ray-casting using three different target assistance techniques—two motor-space techniques (sticky targets and a novel form of target gravity), and one acquisition-feedback technique that combined visual, tactile, and auditory feedback. Our first three studies tested each assistance technique separately, to explore how different parameters for each method affected performance and perceptibility. Our fourth study carried out a direct comparison of the best versions of each technique, and also examined the effects of distractor objects placed in the path to the target. Our studies found that the two motor-space techniques were extremely effective in improving selection accuracy without being highly obvious to users, and that the new gravity-based technique (which attracts the cursor even when it is not over the target) performed best of all. There was no observed effect on performance when the combined acquisition-feedback technique was used. Our studies are the first to comprehensively explore the optimization, performance, and perceptibility of target assistance techniques for relative ray-casting—our results provide designers with clear guidelines about what methods to use, how to configure the techniques, and what effects can be expected from their use.
- ItemOpen AccessArtifact awareness through screen sharing for distributed groups(2008-06-16T22:25:36Z) Greenberg, Saul; Tee, Kimberly; Gutwin, CarlWhen co-located, people can see the artifacts that others are working on, which in turn enables casual interactions. To help distributed groups maintain mutual awareness of people’s electronic work artifacts, we designed and implemented an awareness tool that leverages screen sharing methods. People see portions of others' screens in miniature, can selectively raise larger views of a screen to get more detail, and can engage in remote pointing. People balance awareness with privacy by using several privacyprotection strategies built into the system. An evaluation with two groups using this system shows that people use it to: maintain awareness of what others are doing, project a certain image of themselves, monitor progress, coordinate joint tasks, determine others’ availability, and engage in serendipitous conversation and collaboration. While privacy was not a large concern for these groups, a theoretical analysis suggests that privacy risks may differ for other user communities.
- ItemMetadata onlyAwareness beyond the desktop: exploring attention and distraction with a projected peripheral-vision display(Canadian Information Processing Society, 2010) Birnholtz, Jeremy; Reynolds, Lindsay; Luxenberg, Eli; Gutwin, Carl; Mustafa, MaryamThe initiation of interaction in face-to-face settings is often a gradual negotiation process that takes place in a rich context of awareness and social signals. This gradual approach to interaction is missing from most online messaging systems, however, and users often have no idea when others are paying attention to them or when they are about to be interrupted. One reason for this limitation is that few systems have considered the role of peripheral perception in attracting and directing interpersonal attention in face-to-face interaction. We believed that a display exploiting people's peripheral vision could capitalize on natural human attention-management behavior. To test the value of this technique, we compared a peripheral-vision awareness display with an on-screen IM-style system. We expected that people would notice more information from the larger peripheral display, which they did. Moreover, they did so while attending less often to the peripheral display. Our study suggests that peripheral-vision awareness displays may be able to improve attention and awareness management for distributed groups.
- ItemMetadata onlyCharacterizing Deixis over Surfaces to Improve Remote Embodiments(2011) Genest, Aaron; Gutwin, Carl
- ItemOpen AccessCombining Power and Simplicity in a Groupware Toolkit(2009-03-02T20:27:23Z) de Alwis, Brian; Gutwin, Carl; Greenberg, SaulMany tools exist for the development of real-time distributed groupware, but most of these tools do not provide an appropriate balance of power and simplicity necessary for prototyping or research. To better support the middle ground in groupware development, we built a new toolkit called GT/SD. It provides solutions to problems of real-world network performance without sacrificing the simple programming approach needed for rapid prototyping. GT/SD builds on the successes both of earlier groupware toolkits and game networking libraries, and implements seven ideas that help solve problems of rapid development, network delay, quality of service, and testing. We introduce the design and the benefits of GT/SD, and demonstrate the toolkit through several examples.
- ItemMetadata onlyComparing awareness and distraction between desktop and peripheral-vision displays(ACM, 2010) Reynolds, Lindsay; Birnholtz, Jeremy; Luxenberg, Eli; Gutwin, Carl; Mustafa, MaryamWe tested a peripheral-vision display to provide users with awareness of others and their level of interest in interaction in an experiment where participants had to be aware of a simulated workgroup during a visually-demanding primary task. Participants gathered more information from the peripheral-vision display although they attended to it significantly less often (less than half the number of glances, and less than a third of the total time spent looking). Our results suggest that the peripheral-vision space around the user is a valuable resource for awareness and communication systems.
- ItemMetadata onlyA Comparison of Techniques for In-place Toolbars(ACM, 2010) Doucette, Andre; Gutwin, Carl; Mandryk, Regan L.Selections are often carried out using toolbars that are located far away from the location of the cursor. To reduce the time to make these selections, researchers have proposed in-place toolbars such as Toolglasses or popup palettes. Even though in-place toolbars have been known for a long time, there are factors influencing their performance that have not been investigated. To explore the subtleties of different designs for in-place toolbars, we implemented and compared three approaches: warping the cursor to the toolbar, having the toolbar pop up over the cursor, and showing the toolbar on the trackpad itself to allow direct touch. Our study showed that all three new techniques were faster than traditional static toolbars, but also uncovered important differences between the three in-place versions. Participants spent significantly less time in the direct-touch trackpad, and warping the cursor's location caused a time-consuming attentional shift. These results provide a better understanding of how small changes to in-place toolbar techniques can affect performance.
- ItemOpen AccessDESIGN FOR INDIVIDUALS, DESIGN FOR GROUPS:TRADEOFFS BETWEEN POWER AND WORKSPACE AWARENESS(1998-04-01) Gutwin, Carl; Greenberg, SaulUsers of synchronous groupware systems act both as individuals and as members of a group, and designers must try to support both roles. However, the requirements of individuals and groups often conflict, forcing designers to support one at the expense of the other. The tradeoff is particularly evident in the design of interaction techniques for shared workspaces. Individuals demand powerful and flexible means for interacting with the workspace and its artifacts, while groups require information about each other to maintain awareness. Although these conflicting requirements present real problems to designers, the tension can be reduced in some cases. We consider the tradeoff in three areas of groupware design: workspace navigation, artifact manipulation, and view representation. We show techniques such as multiple viewports, process feedthrough, action indicators, and view translations that support the needs of both individuals and groups.
- ItemOpen AccessEFFECTS OF AWARENESS SUPPORT ON GROUPWARE USABILITY(1997-09-01) Gutwin, Carl; Greenberg, SaulCollaboration in current real-time groupware systems is often an awkward and clumsy process. We hypothesize that better support for workspace awareness can improve the usability of these shared computational workspaces. We conducted an experiment that compared people's performance on two versions of a groupware interface. The interfaces used workspace miniatures to provide different levels of support for workspace awareness. The basic miniature showed information only about the local user, and the enhanced miniature showed the location and activity of others in the workspace as well. In two of three task types tested, completion times were lower with increased awareness support, and in one task type, communication was more efficient. Participants also greatly preferred the awareness-enhanced system. The study provides empirical evidence of, and underlying reasons for, the value of supporting workspace awareness in groupware.
- ItemMetadata onlyEffects of gamification on participation and data quality in a real-world market research domain(ACM, 2013) Cechanowicz, Jared; Gutwin, Carl; Brownell, Briana; Goodfellow, LarryGamification has become an increasingly popular way to improve user engagement and motivation, but there is currently a lack of empirical research to demonstrate that increased gamification provides these benefits. To help address this problem we designed three versions of a gamified market research survey and tested them alongside the established industry standard in a study of over 600 participants. We also highlight examples where game elements compromise respondent data, and provide design solutions that correct the problem without losing the motivational benefits of gamification.
- ItemMetadata onlyThe effects of tactile feedback and movement alteration on interaction and awareness with digital embodiments(ACM, 2013) Doucette, Andre; Mandryk, Regan L.; Gutwin, Carl; Nacenta, Miguel; Pavlovych, AndriyCollaborative tabletop systems can employ direct touch, where people's real arms and hands manipulate objects, or indirect input, where people are represented on the table with digital embodiments. The input type and the resulting embodiment dramatically influence tabletop interaction: in particular, the touch avoidance that naturally governs people's touching and crossing behavior with physical arms is lost with digital embodiments. One result of this loss is that people are less aware of each others' arms, and less able to coordinate actions and protect personal territories. To determine whether there are strategies that can influence group interaction on shared digital tabletops, we studied augmented digital arm embodiments that provide tactile feedback or movement alterations when people touched or crossed arms. The study showed that both augmentation types changed people's behavior (people crossed less than half as often) and also changed their perception (people felt more aware of the other person's arm, and felt more awkward when touching). This work shows how groupware designers can influence people's interaction, awareness, and coordination abilities when physical constraints are absent.
- ItemMetadata onlyEffects of view, input device, and track width on video game driving(Canadian Human-Computer Communications Society, 2011) Bateman, Scott; Doucette, Andre; Xiao, Robert; Gutwin, Carl; Mandryk, Regan L.; Cockburn, AndySteering and driving tasks -- where the user controls a vehicle or other object along a path -- are common in many simulations and games. Racing video games have provided users with different views of the visual environment -- e.g., overhead, first-person, and third-person views. Although research has been done in understanding how people perform using a first-person view in virtual reality and driving simulators, little empirical work has been done to understand the factors that affect performance in video games. To establish a foundation for thinking about view in the design of driving games and simulations, we carried out three studies that explored the effects of different view types on driving performance. We also considered how view interacts with difficulty and input device. We found that although there were significant effects of view on performance, these were not in line with conventional wisdom about view. Our explorations provide designers with new empirical knowledge about view and performance, but also raise a number of new research questions about the principles underlying view differences.
- ItemOpen AccessTHE EFFECTS OF WORKSPACE AWARENESS SUPPORT ON THE USABILITY OF REAL-TIME DISTRIBUTED GROUPWARE(1998-10-01) Gutwin, Carl; Greenberg, SaulReal-time collaboration in current groupware workspace is often an awkward and clumsy process. We hypothesize that better support for workspace awareness - the understanding of who is in the workspace, where they are working, and what they are doing - can improve the usability of these shared computational workspaces. We conducted an experiment that compared people's performance on two versions of a groupware interface. The interfaces used workspace miniatures to provide different levels of support for workspace awareness. The basic miniature showed information only about the local user, and the enhanced miniature showed the location and activity of other people in the workspace as well. We examined five aspects of groupware usability: task completion times, communication efficiency, the participants' perceived effort, overall preference, and strategy use. In two of three task types tested, completion times were lower in the awareness-enhanced system, and in one task type, communication was more efficient. The additional awareness information also allowed people to use different and more effective strategies to complete the tasks. Participants greatly preferred the awareness-enhanced system. The study provides empirical evidence that support for workspace awareness improves the usability of groupware, and also uncovers some of the reasons underlying this improvement.
- ItemOpen AccessEMPIRICAL DEVELOPMENT OF A HEURISTIC EVALUATION METHODOLOGY FOR SHARED WORKSPACE GROUPWARE(2002-02-12) Baker, Kevin; Greenberg, Saul; Gutwin, CarlGood real time groupware products are hard to develop, in part because evaluating their support for the basic activities of teamwork is difficult and costly. To address this problem, we are developing discount evaluation methods that look for groupware-specific usability problems. In a previous paper, we detailed a new set of usability heuristics that evaluators can use to inspect shared workspace groupware to see how they support for teamwork. We wanted to determine whether the new heuristics could be integrated into a low-cost methodology that parallels Nielsen's traditional heuristic evaluation (HE). To this end, we examined 27 evaluations of two shared workspace groupware systems and analysed the inspectors' relative performance and variability. Similar to Nielsen's findings for traditional HE, individual inspectors discovered about a fifth of the total known teamwork problems, and that there was only modest overlap in the problems they found. Groups of three to five inspectors would report about 40-60% of the total known teamwork problems. These results suggest that heuristic evaluation using our groupware heuristics can be an effective and efficient method for identifying teamwork problems in shared workspace groupware systems.
- ItemMetadata onlyGone but not forgotten: designing for disconnection in synchronous groupware(ACM, 2010) Gutwin, Carl; Graham, T.C. Nicholas; Wolfe, Chris; Wong, Nelson; de Alwis, BrianSynchronous groupware depends on the assumption that people are fully connected to the others in the group, but there are many situations (network delay, network outage, or explicit departure) where users are disconnected for various periods. There is little research dealing with disconnection in synchronous groupware from a user and application perspective; as a result, most current groupware systems do not handle disconnection events well, and several user-level problems occur. To address this limitation, we developed the Disco framework, a model for handling several types of disconnection in synchronous groupware. The framework considers how disconnections are identified, what senders and receivers should do during an absence, and what should be done with accumulated data upon reconnection. We have implemented the framework in three applications that show the feasibility, generality, and functionality of our ideas. Our framework is the first to deal with a full range of disconnection issues for synchronous groupware, and shows how groupware can better support the realities of distributed collaboration.
- ItemOpen AccessHEURISTIC EVALUATION OF GROUPWARE BASED ON THE MECHANICS OF COLLABORATION(2000-10-13) Baker, Kevin; Greenberg, Saul; Gutwin, CarlDespite the increasing availability of groupware, most systems are awkward and not widely used. While there are reasons for this, a significant problem is that groupware is difficult to evaluate. In particular, there are no discount usability evaluation methodologies that can discover problems specific to teamwork. In this paper, we describe how we adapted Nielsen's heuristic evaluation methodology, designed originally for single user applications, to help inspectors rapidly, cheaply and effectively identify usability problems within groupware systems. Specifically, we take the 'mechanics of collaboration'framework and restate it as heuristics for the purposes of discovering problems in shared visual work surfaces for distance-separated groups.
- ItemMetadata onlyThe human factors of consistency maintenance in multiplayer computer games(ACM, 2010) Savery, Cheryl; Graham, T.C. Nicholas; Gutwin, CarlConsistency maintenance (CM) techniques are a crucial part of many distributed systems, and are particularly important in networked games. In this paper we describe a framework of the human factors of CM, to help designers of networked games make better decisions about its use. The framework shows that there is wide variance in the CM requirements of different game situations, identifies the types of requirements that can be considered, and analyses the effects of several consistency schemes on user experience factors. To further explore these issues, we carried out a simulation study that compared four CM algorithms. The experiment confirms many of the predictions of the framework, and reveals additional subtleties of the algorithms. Our work is the first to look comprehensively at the tradeoffs and costs of CM, and our results are a strong starting point that will help designers improve on the user's quality of experience in distributed shared environments.
- ItemOpen AccessTHE IMPORTANCE OF AWARENESS FOR TEAM COGNITION IN DISTRIBUTED COLLABORATION(2001-12-18) Gutwin, Carl; Greenberg, SaulAlthough the phrase team cognition suggests something that happens inside people's heads, teams are very much situated in the real world, and there are a number of things that have to happen out in that world for teams to be able to think and work together. This is not just spoken communication. Depending on the circumstances, effective team cognition includes things like using environmental cues to establish a common ground of understanding, seeing who is around and what they are doing, monitoring the state of artifacts in a shared work setting, noticing other people's gestures and what they are referring to, and so on (Clark, 1996; Hutchins, 1996). In this chapter, we will argue that awareness of other group members is a critical building block in the construct of team cognition, and consequently that computational support for awareness in groupware systems is crucial for supporting team cognition in distributed groups. Our main message is that: for people to sustain effective team cognition when working over a shared visual workspace, our groupware systems must give team members a sense of workspace awareness. Before getting into details, we will set the scene by first describing the collaborative situations we address in this chapter, and then by introducing workspace awareness and why it is a problem in conventional groupware systems.