Eva-Lotta Sallnäs

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.

Effects of communication mode on social presence, virtual presence, and performance in collaborative virtual environments

How does communication mode affect peoples experience of social presence, presence, and performance, and how does it affect their actual collaboration in a virtual environment? In a first experiment, subjects communicated by text-chat, audio conference, or video conference in a desktop collaborative virtual environment (CVE). Both perceived social presence and presence were shown to be lower in the text-chat condition than in the audio- and video-conference conditions. People spent a longer time performing a decision-making task together, spoke fewer words in total, and also spoke fewer words per second in the text-chat environment. Finally, more words per second were spoken in the audio-conference than in the video-conference condition. In a second experiment, collaboration in a CVE audio- and a CVE video condition was compared to collaboration in a Web audio-conference and a Web video-conference condition. Results showed that presence was rated higher in the two video than in the two audio conditions and especially in the Web video condition. People spent more time in the video than in the audio conditions and more words per second were spoken in the Web than in the CVE conditions. In conclusion, it was found that both the communication media used and the environment in which collaboration takes place (CVE or Web) make a difference for how subjects experience interaction and for their communication behavior.

Collaboration in multi-modal virtual worlds: comparing touch, text, voice and video

Social aspects of virtual reality is an area of research that has expanded as the technology has matured. Collaborative virtual environments (CVEs) show great promise for investigating how human-human interaction works. The reason for this is that the mode of communication as well as task contexts, spatial affordances, information presentation and manipulation of common objects can be varied in order to understand the effects of - and interrelations between - these factors. The communication mode is often text-chat in virtual environments, and audio or video channels are used less often. It has only recently become possible to support other human senses like touch in three-dimensional virtual environments. In this chapter my main interest is in comparing the different communication modes, such as textchat, voice communication and video conferencing, and investigating the effect of supporting the touch modality. Evaluation of collaboration through different communication modes is not as common in the area of CVEs as in the area of telecommunications and computer-mediated communication (CMC). One reason for this is that social psychology has not had a large impact on research in the field of CVEs. In social psychological studies of mediated interaction, the focus of interest is, for example, on how people can build and sustain relations, prevent and solve conflicts, and collaborate to attain joint goals [1]. A general argument that a number of theories make is that the social richness of the communication medium has to be matched with the task in order for collaborators to accomplish these

A user-centered designed FOSS implementation of bone surgery simulations

Different aspects of bone surgery simulation has been a popular topic in haptics research field. This demonstration paper has two major results: a Free and Open Source Software (FOSS) implementation of a well known algorithm for tool-bone interaction force estimation, and an evaluation conducted as part of a suggested User-centered design approach for creation of a surgery simulator targeting Oral Surgery in particular.

Communicative Functions of Haptic Feedback

In this paper a number of examples are presented of how haptic and auditory feedback can be used for deictic referencing in collaborative virtual environments. Haptic feedback supports getting a shared frame of reference of a common workspace when one person is not sighted and makes haptic deictic referencing possible during navigation and object exploration. Haptic guiding is a broader concept that implies that not only a single action, like a deictic reference, is made but that a whole sequence of temporally connected events are shared, sometimes including deictic referencing. In the examples presented in this paper haptic guiding is used by participants as a way to navigate while at the same time explore details of objects during joint problem solving. Guiding through haptic feedback is shown to substitute verbal navigational instructions to a considerable extent.

Navigational abilities in audial voice-controlled dialogue structures

Four audial navigation structure conditions, designed to support a voice messaging service, each demanding a different degree of cognitive load, were assessed by 40 naive subjects in groups of 10. Three were voice-controlled: Hierarchical , Flexible (direct, no menus) and Guided (Yes/No) and one was keypad-controlled: hierarchical. Voice recognition was simulated by means of a Wizard-of-Oz set-up. The four subject groups were matched regarding spatial ability (High/ Low) as measured by the Duremann-Salde battery. Initial interaction performance was observed over six tasks, without providing the subjects with a conceptual model of the navigation structure or an appropriate command syntax. Neither number of completed tasks (4.6-5.1 out of 6), total completion time (701-849 s), nor subjective attitudes differed significantly across navigation conditions. The simple optimum path measure was significant, favouring the guided (4.1 out of 6) as compared to the flexible structure (2.5 out of 6). A significant int...

Improved Precision in Mediated Collaborative Manipulation of Objects by Haptic Force Feedback

The extent that haptic force feedback affects peoples ability to collaborate in a mediated way has not been investigated much. In this paper an experiment is presented where collaboration in a distributed desktop virtual environment with haptic force feedback was studied. A video analysis of the frequency of failures to lift cubes collaboratively in a haptic condition compared to a condition with no haptic force feedback was conducted. The frequency of failures to lift cubes collaboratively is a measure of precision in task performance. The statistical analysis of the data shows that it is significantly more difficult to lift objects collaboratively in a three-dimensional desktop virtual environment without haptic force feedback.

WoodenHaptics: A Starting Kit for Crafting Force-Reflecting Spatial Haptic Devices

Spatial haptic interfaces have been around for 20 years. Yet, few affordable devices have been produced, and the design space in terms of physical workspace and haptic fidelity of devices that have been produced are limited and discrete. In this paper, an open-source, open-hardware module-based kit is presented that allows an interaction designer with little electro-mechanical experience to manufacture and assemble a fully working spatial haptic interface. It also allows for modification in shape and size as well as tuning of parameters to fit a particular task or application. Results from an evaluation showed that the haptic quality of the WoodenHaptics device was on par with a Phantom Desktop and that a novice could assemble it with guidance in a normal office space. This open source starting kit, uploaded free-to-download online, affords sketching in hardware; it unsticks the hardware from being a highly-specialized and esoteric craft to being an accessible and user-friendly technology, while maintaining the feel of high-fidelity haptics.

Haptic feedback increases perceived social presence

Passing an object between two people is a common event that happens in various forms for example when giving someone a cup of coffee. An experimental study is presented where passing objects between two people in a virtual environment with haptic feedback was compared to passing objects in a nonhaptic virtual environment. The aim of the experiment was to investigate if and how added haptic feedback in such an environment affects perceived virtual presence, perceived social presence and perceived task performance. A within subject design was used, were nine pairs of subjects performed a hand off task with six differently sized cubes without audio communication. Results showed that haptic force feedback significantly improved perceived virtual presence, perceived social presence and perceived performance in this experiment.

Audio makes a difference in haptic collaborative virtual environments

In this paper a study is presented which aimed at exploring the effects of audio feedback in a haptic and visual interface supporting collaboration among sighted and people who cannot see. A between group design was used and the participants worked in pairs with one sighted and one blindfolded in each. The application used was a haptic 3D environment in which participants could build composed objects out of building blocks. The building blocks could be picked up and moved around by means of a touch feedback pointing device. In one version of the application, used by half of the groups, sound cues could be used to tell the other person where you were, and to get feedback on your own and the other persons actions. Results showed that sound cues together with haptic feedback made a difference in the interaction between the collaborators regarding their shared understanding of the workspace and the work process. Especially, sound cues played an important role for maintaining awareness of ongoing work - you knew what was going on, and you got a response on your own actions.