Empirical development of a heuristic evaluation methodology for shared workspace groupware

Good real time groupware products are hard to develop, in part because evaluating their support for basic teamwork activities 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 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

All across the circle : using auto-ordering to improve object transfer between mobile devices

People frequently form small groups in many social and professional situations: from conference attendees meeting at a coffee break, to siblings gathering at a family barbecue. These ad-hoc gatherings typically form into predictable geometries based on circles or circular arcs (called F-Formations). Because our lives are increasingly stored and represented by data on handheld devices, the desire to be able to share digital objects while in these groupings has increased. Using the relative position in these groups to facilitate file sharing can enable intuitive techniques such as passing or flicking. However, there is no reliable, lightweight, ad-hoc technology for detecting and representing relative locations around a circle. In this paper, we present two systems that can auto-order locations about a circle based on sensors that are standard on commodity smartphones. We tested these systems using an object-passing task in a laboratory environment against unordered and proximity-based systems, and show that our techniques are faster, are more accurate, and are preferred by users.Postprin

The effects of changing projection geometry on perception of 3D objects on and around tabletops

Funding: Natural Sciences and Engineering Research Council of Canada Networks of Centres of Excellence of Canada.Displaying 3D objects on horizontal displays can cause problems in the way that the virtual scene is presented on the 2D surface; inappropriate choices in how 3D is represented can lead to distorted images and incorrect object interpretations. We present four experiments that test 3D perception. We varied projection geometry in three ways: type of projection (perspective/parallel), separation between the observer’s point of view and the projection’s center (discrepancy), and the presence of motion parallax (with/without parallax). Projection geometry had strong effects different for each task. Reducing discrepancy is desirable for orientation judgments, but not for object recognition or internal angle judgments. Using a fixed center of projection above the table reduces error and improves accuracy in most tasks. The results have far-reaching implications for the design of 3D views on tables, in particular for multi-user applications where projections that appear correct for one person will not be perceived correctly by another.PostprintPeer reviewe

Réduire l'Aversion aux Erreurs pour Aider la Transition Novice-Expert avec Fast Tap

National audienceExpert interaction techniques such as gestures or hotkeys are more efficient than traditional WIMP techniques because it is often faster to recall a command than to navigate to it. However, many users seem to be reluctant to switch to expert interaction. We hypothesize the cause might be the aversion of making errors. To test this, we designed two intermediate modes for the FastTap interaction technique, allowing quick confirmation of what the user has retrieved from memory, and quick adjustment if she has made an error. We investigated the impact of these modes and of various error costs in a controlled study (N=36). We found that participants adopted the intermediate modes, that these modes reduced error rate when error cost was high, and that they did not substantially change selection times. However, while it validates the design of our intermediate modes, we found no evidence of greater switch to memory-based interaction, suggesting that reducing the error rate is not sufficient to promote expert use of techniques.Les techniques d'interaction expertes comme les vocabulaires gestuels ou les raccourcis clavier sont plus efficaces que les techniques WIMP traditionnelles. Il est en effet plus rapide de se rappeler une commande plutôt que de la retrouver dans des menus. Cependant, la plupart des utilisateurs semblent réticents à passer aux interactions qui se basent sur leur mémoire. Nous pensons que la cause pourrait être due à leur aversion à faire des erreurs. Pour tester cette hypothèse, nous avons conçu deux modes intermédiaires pour la technique d'interaction FastTap, qui permet de rapidement confirmer ce que l'utilisateur s'est rappelé de mémoire, et d'ajuster si une erreur a été faite. Nous avons étudié l'impact de ces deux modes intermédiaires et de différents coûts d'erreur dans une étude contrôlée (N=36). Nous avons trouvé que les participants ont adopté les modes intermédiaires, que ces modes réduisaient le taux d'erreur quand le coût de l'erreur était important, et qu'ils n'ont pas affecté de manière significative les temps de sélection. Cependant, bien que les résultats valident la conception de nos modes intermédiaires, nous n'avons pas trouvé de preuve sur un plus grand passage aux interactions qui se basent sur la mémoire. Cela suggère que réduire le taux d'erreur n'est pas suffisant pour promouvoir l'utilisation experte des techniques

Providing artifact awareness to a distributed group through screen sharing

Despite the availability of awareness servers and casual interaction systems, distributed groups still cannot maintain artifact awareness the easy awareness of the documents, objects, and tools that other people are using that is a natural part of co-located work environments. To address this deficiency, we designed an awareness tool that uses screen sharing to provide information about other people s artifacts. People see others screens in miniature at the edge of their display, can selectively raise a larger view of that screen to get more detail, and can engage in remote pointing if desired. Initial experiences show that people use our tool for several purposes: to maintain awareness of what others are doing, to project a certain image of themselves, to monitor progress and coordinate joint tasks, to help determine when another person can be interrupted, and to engage in serendipitous conversation and collaboration. People have also been able to balance awareness with privacy, by using the privacy protection strategies built into our system: restricting what parts of the screen others can see, specifying update frequency, hiding image detail, and getting feedback of when screenshots are taken.We are currently acquiring citations for the work deposited into this collection. We recognize the distribution rights of this item may have been assigned to another entity, other than the author(s) of the work.If you can provide the citation for this work or you think you own the distribution rights to this work please contact the Institutional Repository Administrator at [email protected]

iVoLVER : Interactive Visual Language for Visualization Extraction and Reconstruction

We present the design and implementation of iVoLVER, a tool that allows users to create visualizations without textual programming. iVoLVER is designed to enable flexible acquisition of many types of data (text, colors, shapes, quantities, dates) from multiple source types (bitmap charts, webpages, photographs, SVGs, CSV files) and, within the same canvas, supports transformation of that data through simple widgets to construct interactive animated visuals. Aside from the tool, which is web-based and designed for pen and touch, we contribute the design of the interactive visual language and widgets for extraction, transformation, and representation of data. We demonstrate the flexibility and expressive power of the tool through a set of scenarios, and discuss some of the challenges encountered and how the tool fits within the current infovis tool landscape.Postprin

A comparison of guiding techniques for out-of-view objects in full-coverage displays

Full-coverage displays can place visual content anywhere on the interior surfaces of a room (e.g., a weather display near the coat stand). In these settings, digital artefacts can be located behind the user and out of their field of view - meaning that it can be difficult to notify the user when these artefacts need attention. Although much research has been carried out on notification, little is known about how best to direct people to the necessary location in room environments. We designed five diverse attention-guiding techniques for full-coverage display rooms, and evaluated them in a study where participants completed search tasks guided by the different techniques. Our study provides new results about notification in full-coverage displays: we showed benefits of persistent visualisations that could be followed all the way to the target and that indicate distance-to-target. Our findings provide useful information for improving the usability of interactive full-coverage environments.PostprintPostprin