Brown University

Funding for Human Subjects Research:

DOE: Office of Advanced Scientific Computing Research

$900,000.00 (Est.) for: Fiscal Year 2005
This figure includes the cost of labor (both direct and indirect charges) involved in designing and conducting a user study as well as participant fees.
Percent of funding associated with the use of human subjects: 1-20

Information on Use of Human Subjects:

This project involves the use of multiple protocols/subprojects.
Number of protocols/subprojects associated with this project: 2

Institutional Review Board (IRB) Review:
Type of Review: Expedited
Approving Institution: Brown University
Most recent approval: 02/23/05
IRB approval number: n/a

Number of human subjects who participated in this project/protocol/subproject in the last reporting period: 13
Reporting period for number of human subjects: Fiscal Year 2005

Type(s) of Human Subjects Involvement:

Use of human beings to develop/test instruments, materials, devices, objects, and the like or to investigate the "man-machine interface".

(a. Objectives, b. Methodology, c. Ionizing Radiation, Radioactive Substances, or Chemical Substances to which human subjects are exposed, d. Involvement of Human Subjects [d.1. procedures used, d.2. risks if any])

a) Objectives:
The goal of this project is to evaluate the usefulness of several immersive environments, including the Cave, Fishtank Virtual Reality (VR), and the Powerwall. The user studies will compare software applications running in different configurations-for example, comparing an application that runs in the Cave to a comparable application that runs on the desktop and in Fishtank VR. Our goal is to understand the relative advantages of each visualization environment.

b) Methodology:
Subjects first fill out a questionnaire asking for basic statistical information like their age group; gender; previous experience with computers, computer graphics applications, virtual reality, and 3D movies; and knowledge about the domain the software is written for.
Subjects are then briefed about the goals of the study and the tasks they will be asked to perform, and they are asked to read and sign the consent form.
In the user studies the subjects work with one visualization environment at a time, in most cases they do not have to work in each of the environments but only a subset. They wear stereo glasses and use instrumented props to interact with the system. The prop devices operate either with electromagnetic fields or ultrasound. Both technologies have been in regular commercial use for over five years with no known side effects for humans.
The software run during the trials will have been written by the researchers in our group and will allow subjects to view and manipulate data sets from domains like biology, medicine, engineering, architecture, or fine art.
After the studies in the visualization environments, subjects will be asked to fill out another questionnaire that asks about their experiences with the system and for additional comments. Finally, an oral debriefing addresses any remaining questions or issues.
The participants can end a trial at any time if they choose to.

c) Radiation/chemicals:
We did not expose our subjects to ionizing radiation, radioactive, or chemical substances.

d) Involvement:
1. Procedures:
The procedures used in the evaluation stem from typical approaches used in the field of computer-human interface research: all subjects will fill out questionnaires before and after their work in our visualization environments. Their performance will be watched by multiple observers from the group of researchers, who take written notes of the subjects' comments and questions. User input data from mouse and/or tracking devices may be stored in disk files to be statistically evaluated at the end of the study. In cases which we consider particularly interesting (e.g., when domain experts use our systems) we may record audio and/or video of the subjects' work in the visualization environments. The acquired data may consist of paper and/or electronic questionnaires, note sheets, computer files, and audio/video recordings.

2. Risks:
We do not anticipate any serious risks or discomforts during the experiments. Minor risks associated with immersive VR are the possibilities of motion sickness, disorientation, and/or falling down. At our institution during the past five years none of the hundreds of Cave users have fallen down and only a few dozen have experienced minor motion sickness. The tracking technology we will use has been in regular commercial use for over five years with no known risks to humans. Nevertheless, because one tracking technology is magnetic-based, we will post signs outside the rooms stating that the tracking systems are in operation so that people with potentially sensitive equipment (e.g., pacemakers) can subsequently elect to not participate. By briefing subjects on what to expect, we believe risks can be minimized.

3. Privacy:
We will keep our subjects' personal data confidential. We will keep three kinds of data from the user studies: notes on paper, audio/video recordings, and computer files. Paper notes and audio/video recordings will be kept in a lockable drawer in the professor's or one of the experimenters' offices. Computer files will be protected by the access restriction feature of our file system so that only the experimenters have access to them. No names will be stored with the data, and any public documents using the data will not reference personal information of any kind.

Institutional Review Board (IRB) Review:
Type of Review: Full Board
Approving Institution: Brown University
Most recent approval: 06/13/05

Number of human subjects who participated in this project/protocol/subproject in the last reporting period: 29
Reporting period for number of human subjects: Fiscal Year 2005

Type(s) of Human Subjects Involvement:

Use of human beings to develop/test instruments, materials, devices, objects, and the like or to investigate the "man-machine interface".

(a. Objectives, b. Methodology, c. Ionizing Radiation, Radioactive Substances, or Chemical Substances to which human subjects are exposed, d. Involvement of Human Subjects [d.1. procedures used, d.2. risks if any])

Interaction in Immersive Virtual Environments (VEs) is intrinsically centered on the physical actions of the user's body. The location of rendered virtual objects is, in contrast, the free choice of the VE application designer. The goal of Dmitri Lemmerman's master's degree project is to explore the effect of the position of rendered graphical "widgets" on user performance.

The particular task we chose is color-matching: using a 3D color picking widget, users were asked to match a target color. The relative position of the widget with respect to the user is tested in three conditions. Specifically, we distinguish between the interaction frame-of-reference (where the user moves his physical body) and the display frame-of-reference (where the graphical feedback appears). While maintaining the same interaction frame-of-reference, we vary the relative position of the display frame-of-reference to be the same as the interaction frame-of-reference (e.g., collocation), to be displayed at a 3-inch offset, and to be displayed at a 2-foot offset from the interaction frame-of-reference. We believe this relationship is not unique to the color picking widget but generalizes to a larger set of 3D widgets in VEs.

Twenty-nine users were tested in a within subjects design. Each subject was asked to match 15 colors in each of the three conditions. A distance scalar was computed based on a perceptual metric. A repeated measures analysis of variance (ANOVA) test on the data revealed a significant main effect of offset with a confidence level of 0.042. Paired sample t-tests between the conditions did show a significant difference between the collocated case and each of the offset cases but did not show a significant difference between the two offset cases.

We believe the results of this study should inform future VE user interface design for real-world applications and spur further experimental research in VEs. Studies in head-mounted display (HMD)-based VEs have demonstrated significant performance advantages to collocation and the "direct manipulation" of virtual objects. Unlike HMD-based systems, our Cave VE platform allows the user to see both his body and the virtual objects. The presence of the user's body appears to degrade performance when it is collocated with the virtual objects on which the user must focus (as it was in one of our conditions). However, even a short offset of 3 inches seems to alleviate this problem.