Reference Frame

Description: This project examines the effect of user location in VR and why it does matter. A user’s location within a virtual environment may play an important role in
the perception of the data and whether a user can relate their own body to the content. In this research, we examined the role of the user’s location in VR on memorization performance.  Figure 1, left, shows a participant that their three main body axes are in full alignment with the characteristics of the representation, which potentially could help them organize and understand the data space, entity locations, and values within it. The participant in Figure 1, right, is partially aligned and the coordinate system is misaligned with the participants’ egocentric perspective such that changes of values along some of the axes are not aligned with the main body axes and not orthogonal from the participant’s point of view. Both conditions were fixed with only a look-around feature so the participant could physically turn around but could not navigate anywhere. Figure 2 shows the VR memorization task performed by participants in the fully aligned condition (left) and the partially aligned condition (right).

Figure 1

Figure 2

Results: Partial or full alignment can affect the user’s perception of spatial phenomena, especially regarding distance judgment. We compared the in-lab data collection with the out-of-lab study (crowdXR). The in-lab study was administered as a traditional experiment with undergraduate students and dedicated VR equipment. The out-of-lab study was carried out remotely by recruiting HMD owners from VR-related research mailing lists, VR subreddits in Reddit, and crowdsourcing platforms. There was no significant main effect of the study or absolute difference in means and variances of distance recall errors along any of the coordinate axes (fully vs partially aligned). Participants in the partially aligned condition made significantly larger distance recall errors along the front-back than along the left-right axis while there was no such difference in the fully aligned condition. For both conditions, participants had smaller distance recall errors along the up-down than along the front-back axis.

The results indicate that the reliability of the data from out-of-lab participants was as good as or better than their in-lab counterparts. Additionally, the data for testing our research hypotheses were comparable between in- and out-of-lab studies. We conclude although the findings are limited, crowdsourcing is a feasible and effective alternative to the use of university participant pools for collecting survey and performance data for VR research, despite potential design issues that may affect the generalizability of study results.

Collaborators: Jiayan Zhao, Mark Simpson, Pejman Sajjadi, Jan Oliver Wallgrün, Ping Li,
Mahda M. Bagher, Danielle Oprean, Lace Padilla, Alexander Klippel

Publication:

Zhao, J., Simpson, M., Sajjadi, P., Wallgrün, J. O., Li, P., Bagher, M. M., … & Klippel, A. (2021, October). Crowdxr-pitfalls and potentials of experiments with remote participants. In 2021 IEEE International Symposium on Mixed and Augmented Reality (ISMAR) (pp. 450-459). IEEE.

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