Kirsten Rassmus-Gröhn

Supporting presence in collaborative environments by haptic force feedback

An experimental study of interaction in a collaborative desktop virtual environment is described. The aim of the experiment was to investigate if added haptic force feedback in such an environment affects perceived virtual presence, perceived social presence, perceived task performance, and task performance. A between-group design was employed, where seven pairs of subjects used an interface with graphic representation of the environment, audio connection, and haptic force feedback. Seven other pairs of subjects used an interface without haptic force feedback, but with identical features otherwise. The PHANToM, a one-point haptic device, was used for the haptic force feedback, and a program especially developed for the purpose provided the virtual environment. The program enables for two individuals placed in different locations to simultaneously feel and manipulate dynamic objects in a shared desktop virtual environment. Results show that haptic force feedback significantly improves task performance, perceived task performance, and pereceived virtual presence in the collaborative distributed environment. The results suggest that haptic force feedback increases perceived social presence, but the difference is not significant.

TouchOver map: audio-tactile exploration of interactive maps

This article reports on a preliminary study, which investigates if vibration and speech feedback can be used in order to make a digital map on a touch screen device more accessible. We test if vibration feedback combined with speech, triggered as the finger moves over relevant map objects, works to make sense of the map content. The study results indicate that it is indeed possible to get a basic overview of the map layout even if a person does not have access to the visual presentation. In the conclusions the interaction problems are indentified and suggestions for future improvements are given.

Pointing for non-visual orientation and navigation

People who have visual impairments may have difficulties navigating freely and without personal assistance, and some are even afraid to go out alone. Current navigation devices with non-visual feedback are quite expensive, few, and are in general focused on routing and target finding. We have developed a test prototype application running on the Android platform in which a user may scan for map information using the mobile phone as a pointing device to orient herself and to choose targets for navigation and be guided to them. It has previously been shown in proof of concept studies that scanning and pointing to get information about different locations, or to use it to be guided to a point, can be useful. In the present study we describe the design of PointNav, a prototype navigational application, and report initial results from a recent test with visually impaired and sighted users.

A real-world study of an audio-tactile tourist guide

This paper reports on the in-context evaluation of an audio-tactile interactive tourist guide - one test was done in a medieval city center, and the other was done at an archaeological site. The activity theory framework was used as a perspective to guide design, field-study and analysis. The evaluation shows that the guide allows users to experience an augmented reality, while keeping the environment in focus (in contrast with the common key-hole like experience that on-screen augmented reality generates). The evaluation also confirms the usefulness of extending the vibrational feedback to convey also distance information as well as directional information.

A virtual traffic environment for people with visual impairments

This article reports results from a study in which ten severely visually impaired users used a virtual haptic-audio traffic environment for exploring and learning a route. The virtual environment was a model of a real traffic environment in Lund, Sweden, and included 484 static objects and 35 dynamic objects (cars and bicycles). Eight of the ten users were able to handle this large and complex environment, and the same users also succeeded in navigating the real traffic section from which the virtual environment was modeled. The users navigating the virtual world most easily were those that also were very good at navigating with a cane. Further results such as the identification of two different exploration strategies in the virtual model, different usages of this kind of model and the importance of relevant initial information are also discussed.

Guiding tourists through haptic interaction: vibration feedback in the lund time machine

This paper describes the vibrationnal feedback that was chosen for the guiding interaction part of the Lund Time Machine application. This tourist guide provides information on points of interests along a trail, and guides the user along it. The interface uses audio and tactile modalities to be accessible in situations where the visual channel is not available. To navigate to the next goal, the user scans around and feels the phone vibrating in the correct direction. The distance coding was embedded in the directional feedback by making the bursts more frequent when getting closer to the goal. The design was first evaluated in a controlled study and then validated as usable and non-obtrusive within an evaluation in the real context of use.

Iterative design of an audio-haptic drawing application

This paper presents the ongoing design and evaluation of an audio-haptic drawing program that allows visually impaired users to create and access graphical images. The application is developed in close collaboration with a user reference group of five blind/low vision school children. The objective of the application is twofold. It is used as a research vehicle to investigate user interaction techniques and do basic research on navigation strategies and help tools, including e.g. sound fields, shape creation tools and beacons with pulling forces in the context of drawing. In the progress of the development, the preferred features have been implemented as standard tools in the application. The final aim of the application in its current form is to aid school work in different subjects, and part of the application development is also to create tasks relevant in a school setting.

Scanning angles for directional pointing

The present study was performed in order to get a better understanding of the influence of the scanning angle interval on navigation performance, gestures and strategies in a more realistic outdoor setting. Results indicate that users are able to handle a wide range of angle intervals. We observe different gestures and strategies and provide recommendations for suitable angle intervals. Our observations also support the notion that using this type of pointing gesture for navigation is intuitive and easy to use.

AHEAD - Audio-Haptic Drawing Editor And Explorer for Education

We present the final evaluation of an audio-haptic editor and explorer for virtual 2D relief drawings that allow visually impaired users to create and explore graphical images. The application has been developed in collaboration with a user reference group of five blind/low vision school children, and has undergone final evaluation during spring in 2007. The AHEAD application has been used to create material that has been successfully used in school work.

The influence of angle size in navigation applications using pointing gestures

One factor which can be expected to influence performance in applications where the user points a device in some direction to obtain information is the angle interval in which the user gets feedback. The present study was performed in order to get a better understanding of the influence of this angle interval on navigation performance, gestures and strategies in a more realistic outdoor setting. Results indicate that users are able to handle quite a wide range of angle intervals, although there are differences between narrow and wide intervals. We observe different gestures and strategies used by the users and provide some recommendations on suitable angle intervals. Finally, our observations support the notion that using this type of pointing gesture for navigation is intuitive and easy to use.