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

An Evaluation of Virtual Lenses for Object Selection in Augmented Reality

This paper reports the results of an experiment to compare three different selection techniques in a tabletop tangible augmented reality interface. Object selection is an important task in all direct manipulation interfaces because it precedes most other manipulation and navigation actions. Previous work on tangible virtual lenses for visualisation has prompted the exploration of how selection techniques can be incorporated into these tools. In this paper a selection technique based on virtual lenses is compared with the traditional approaches of virtual hand and virtual pointer methods. The Lens technique is found to be faster, require less physical effort to use, and is preferred by participants over the other techniques. These results can be useful in guiding the development of future augmented reality interfaces

Flexible Delivery Damaging to Learning? Lessons From the Canterbury

Abstract Preparing courses for flexible delivery and distance education is normally a time-consuming and expensive process. This paper describes the design and evaluation of a system that automatically captures and indexes audio and video streams of traditional university lectures without demanding any changes in the style or tools used by teachers. Using a 'wizard-of-oz' technique to simulate the automatic indexing, we ran a four month trial of the system in a large (746 students) first year Computer Studies course. The results reveal some surprising social implications of making flexible delivery available to students at a residential university. Early in the trial, many students expressed an intention to use the system, but few did. Late in the course, many students stated that they urgently needed the system for revision, but even fewer used it. At the same time, lecture attendance appeared to be lower than normal. We hypothesise that the availability of a flexible alternative to lectures removed the necessity of attending lectures, and that students deceived themselves about their intentions to catch up using the digital medium

Interaction Interferences: Implications of Last-Instant System State Changes

International audienceWe study interaction interferences, situations where an unexpected change occurs in an interface immediately before the user performs an action, causing the corresponding input to be misinterpreted by the system. For example, a user tries to select an item in a list, but the list is automatically updated immediately before the click, causing the wrong item to be selected. First, we formally define interaction interferences and discuss their causes from behavioral and system-design perspectives. Then, we report the results of a survey examining users' perceptions of the frequency, frustration, and severity of interaction interferences. We also report a controlled experiment , based on state-of-the-art experimental protocols from neuroscience, that explores the minimum time interval, before clicking, below which participants could not refrain from completing their action. Finally, we discuss our findings and their implications for system design, paving the way for future work

Design and evaluation of braced touch for touchscreen input stabilisation.

Incorporating touchscreen interaction into cockpit flight systems offers several potential advantages to aircraft manufacturers, airlines, and pilots. However, vibration and turbulence are challenges to reliable interaction. We examine the design space for braced touch interaction, which allows users to mechanically stabilise selections by bracing multiple fingers on the touchscreen before completing selection. Our goal is to enable fast and accurate target selection during high levels of vibration, without impeding interaction performance when vibration is absent. Three variant methods of braced touch are evaluated, using doubletap, dwell, or a force threshold in combination with heuristic selection criteria to discriminate intentional selection from concurrent braced contacts. We carried out an experiment to test the performance of these methods in both abstract selection tasks and more realistic flight tasks. The study results confirm that bracing improves performance during vibration, and show that doubletap was the best of the tested methods

An Evaluation Of Integrated Zooming and Scrolling On Small-Screens

Speed-dependent automatic zooming (SDAZ) has been proposed for standard desktop displays as a means of overcoming problems associated with the navigation of large information spaces. SDAZ combines zooming and panning facilities into a single operation, with the magnitude of both factors dependent on simple user interaction. Previous research indicated dramatic user performance improvements when using the technique for document and map tasks. In this paper we propose algorithmic extensions to the technique for application on small-screen devices and present a comparative experimental evaluation of user performance with the system and a normative scroll-zoom-pan interface. Users responded positively to the system, particularly in relation to reduced physical navigational workload. However, the reduced screen space reduced the impact of SDAZ in comparison to that reported in previous studies. In fact, for one-dimensional navigation (vertical document navigation) the normative interface out-performed SDAZ. For navigation in two dimensions (map browsing) SDAZ supports more accurate target location, but also produces longer task completion times. Some SDAZ users became lost within the information space and were unable to recover navigational context. We discuss the reasons for these observations and suggest ways in which limitations of SDAZ in the small-screen context may be overcome

Revisiting read wear: analysis, design, and evaluation of a footprints scrollbar

In this paper, we show that people frequently return to previously-visited regions within their documents, and that scrollbars can be enhanced to ease this task. We analysed 120 days of activity logs from Microsoft Word and Adobe Reader. Our analysis shows that region revisitation is a common activity that can be supported with relatively short recency lists. This establishes an empirical foundation for the design of an enhanced scrollbar containing scrollbar marks that helps people return to previously visited document regions. Two controlled experiments show that scrollbar marks decrease revisitation time, and that a large number of marks can be used effectively. We then design an enhanced Footprints scrollbar that supports revisitation with several features, including scrollbar marks and mark thumbnails. Two further experiments show that the Footprints scrollbar was frequently used and strongly preferred over traditional scrollbars

Promoting Hotkey Use through Rehearsal with ExposeHK

International audienceKeyboard shortcuts allow fast interaction, but they are known to be infrequently used, with most users relying heavily on traditional pointer-based selection for most commands. We describe the goals, design, and evaluation of ExposeHK, a new interface mechanism that aims to increase hotkey use. ExposeHK’s four key design goals are: 1) enable users to browse hotkeys; 2) allow non-expert users to issue hotkey commandsas a physical rehearsal of expert performance; 3) exploit spatial memory to assist non-expert users in identifying hotkeys; and 4) maximise expert performance by using consistent shortcuts in a flat command hierarchy. ExposeHK supports these objectives by displaying hotkeys overlaid on their associated commands when a modifier key is pressed. We evaluated ExposeHK in three empirical studies using toolbars, menus, anda tabbed ‘ribbon’ toolbar. Results show that participants used more hotkeys, and used them more often, with ExposeHK than with other techniques; they were faster with ExposeHK than with either pointing or other hotkey methods; and they strongly preferred ExposeHK. Our research shows that ExposeHK cansubstantially improve the user’s transition from a ‘beginner mode’ of interaction to a higher level of expertise

SensaBubble: a chrono-sensory mid-air display of sight and smell

We present SensaBubble, a chrono-sensory mid-air display system that generates scented bubbles to deliver information to the user via a number of sensory modalities. The system reliably produces single bubbles of specific sizes along a directed path. Each bubble produced by SensaBubble is filled with fog containing a scent relevant to the notification. The chrono-sensory aspect of SensaBubble means that information is presented both temporally and multimodally. Temporal information is enabled through two forms of persistence: firstly, a visual display projected onto the bubble which only endures until it bursts; secondly, a scent released upon the bursting of the bubble slowly disperses and leaves a longer-lasting perceptible trace of the event. We report details of SensaBubble’s design and implementation, as well as results of technical and user evaluations. We then discuss and demonstrate how SensaBubble can be adapted for use in a wide range of application contexts – from an ambient peripheral display for persistent alerts, to an engaging display for gaming or education

Push-Edge and Slide-Edge: Scrolling by Pushing Against the Viewport Edge

International audienceEdge-scrolling allows users to scroll a viewport while simultaneously dragging near or beyond a window’s edge. Common implementations rely on rate control, mapping the distance between the pointer and the edge of the viewport to the scrolling velocity. While ubiquitous in operating systems, edge-scrolling has received little attention, even though previous works suggest that (1) rate control may be suboptimal for isotonic pointing devices like mice and trackpads and (2) space beyond the window’s edge might be scarce, limiting scrolling control. To address these problems, we developed Push-edge scrolling (and Slide-edge scrolling, its inertial variant), two novel position-based techniques that allow scrolling by ‘pushing’ against the viewport edge. A controlled experiment shows that our techniques reduce overshoots and offer performance improvements by up to 13% over traditional edge-scrolling