Sicknificant Steps: A Systematic Review and Meta-analysis of VR Sickness in Walking-based Locomotion for Virtual Reality

Document Title

Sicknificant Steps: A Systematic Review and Meta-analysis of VR Sickness in Walking-based Locomotion for Virtual Reality

Document Information

• Subject Area: Research on motion sickness related to walking-based locomotion in virtual reality
• Keywords: sickness, walking, virtual, reality, vr, ssq, locomotion, vrise

Research Background and Issues

• Issues and Challenges:
  • Walking-based locomotion techniques in virtual reality (VR) enable users to achieve greater spatial movement within physical spaces through redirection; however, these techniques often lead to mismatches between perceived virtual motion and actual physical movement, triggering VR sickness.
  • The literature has yet to clearly define the differences in VR sickness effects among various walking-based locomotion techniques (e.g., resetting, redirection, or overlapping spaces).
  • Experimental results exhibit significant variability, and there is currently a lack of consistency in methods for measuring and reporting VR sickness.
• Research Importance:
  • Walking-based locomotion techniques offer significant advantages in enhancing spatial perception, improving user experience, and boosting task performance. However, users can only fully benefit from these advantages if VR sickness-related issues are effectively addressed.
• Motivation and Related Work:
  • Recent reviews have pointed out that hardware specifications, application characteristics, and user traits all influence VR sickness; however, the specific relationship between walking techniques and VR sickness remains controversial.
  • Based on existing literature, the authors conducted a systematic review and meta-analysis of walking-based locomotion techniques and VR sickness, extending the current classification framework and providing clearer practical guidance.

Proposed Solution

• Research Methods:
  • A systematic review and meta-analysis covering 96 papers published between 2016 and 2022 that focused on walking-based VR locomotion techniques and reported VR sickness measurements.
  • Systematic literature screening following PRISMA guidelines, grouping and evaluating studies based on types of walking-based locomotion techniques.
  • Using the Simulator Sickness Questionnaire (SSQ) as the primary measurement tool and analyzing its applicability and potential issues.
• Innovations:
  • Extending the existing classification system for walking-based techniques and providing detailed guidelines for different types of technologies.
  • Quantitatively comparing the VR sickness effects of various walking redirection techniques and exploring the differences among resetting, relocation, and scene manipulation techniques.
• Implementation Steps:
  • Establishing a literature search and screening process, ultimately selecting 96 eligible papers.
  • Extracting user experience data from each study, including SSQ total scores, experimental conditions, and user characteristics.
  • Conducting meta-analysis to verify significant differences in VR sickness effects across different walking techniques.

Research Findings

• Specific Results:
  • Standard equidistant walking techniques generally result in lower VR sickness compared to non-equidistant redirection techniques, although SSQ total scores remain above zero.
  • Resetting techniques typically induce lower VR sickness compared to other types of redirection techniques (SSQ-TS = 13.21±1.76).
  • Non-equidistant relocation and redirection techniques (e.g., scene manipulation) show significant differences in their impact on VR sickness, with some scene manipulation techniques scoring higher (e.g., SSQ-TS > 30).
• Comparative Advantages:
  • Unlike previous studies that provided qualitative descriptions, this study quantitatively analyzed the VR sickness effects of different walking techniques and provided standardized experimental design details.
  • Offering comparisons between SSQ baseline and post-exposure data, revealing complex relationships between VR sickness and experimental conditions.
• Limitations and Future Directions:
  • The current review exhibits high heterogeneity in the data, with many studies lacking consistent details, limiting the generalizability of the results.
  • Future research should explore the effects of specific user groups (e.g., children, elderly) or experimental conditions (e.g., VR exposure duration).
  • Further development and testing of sickness measurement tools adapted to modern VR hardware are needed to avoid sole reliance on SSQ.

Summary and Guidelines

• Three practical guidelines for measuring and reporting VR sickness:
  1. Ensure accurate calculation and comprehensive reporting of SSQ scores to avoid misinterpretation of sickness ratings.
  2. Carefully consider whether to use SSQ as a pre-exposure measurement tool to reveal symptom differences before and after VR exposure.
  3. Explore other modern VR sickness measurement tools, such as the Cybersickness Questionnaire or Fast Motion Sickness Scale.

Through this review and analysis, the differences in VR sickness effects among walking-based VR locomotion techniques were clarified, providing quantitative references and suggestions for improving measurement methods in future research.