The Fidelity-based Presence Scale (FPS): Modeling the Effects of Fidelity on Sense of Presence

Research Background and Issues

• Identified Problems or Challenges:

  • In the field of Virtual Reality (VR) research, although various questionnaires have been developed to measure the "sense of presence," researchers remain dissatisfied with the ability of these questionnaires to assess how specific VR components influence presence. The lack of a consensus questionnaire or set of items has led researchers to continuously modify or customize existing tools, making results difficult to compare and generalize.
  • Most current questionnaires focus on users' overall subjective perception of the VR environment rather than identifying the contributions of specific components to presence.
  • Additionally, current questionnaires do not consider "fidelity" or "realism" as a critical dimension for measuring its impact on presence.

• Significance:

  • The design of VR systems and the optimization of user experience depend on a deep understanding of how different system components contribute to presence. This understanding not only aids in the development of more immersive VR systems but also promotes practical applications of VR technology and facilitates research comparability.

• Research Motivation and Related Work:

  • The authors draw upon the research framework of system fidelity (interaction fidelity, scenario fidelity, display fidelity) within the field to guide the development of the questionnaire.
  • By analyzing the strengths and weaknesses of existing questionnaire tools (e.g., Igroup Presence Questionnaire, Witmer-Singer Presence Questionnaire), the authors aim to develop a new scale that explicitly reveals the impact of "fidelity" on presence.

Proposed Solution

• Proposed Method or Solution:

  • Fidelity-based Presence Scale (FPS):
    • An innovative questionnaire categorized by fidelity dimensions (interaction, scenario, display) to classify and measure the impact of various VR system components on presence.
  • Employing the Delphi Method to achieve expert consensus in designing the initial questionnaire.
  • Utilizing Exploratory Factor Analysis (EFA) to validate and refine the questionnaire.

• Innovative Aspects of the Solution:

  • Development of the first presence questionnaire centered on "fidelity" and designed through expert consensus.
  • Application of the system fidelity framework to presence measurement tools, overcoming the traditional focus on subjective user experience that fails to pinpoint which specific technological components influence presence.
  • Creation of a tool capable of independently analyzing VR systems through fidelity dimensions, providing concrete guidance for design and optimization.

• Implementation Steps:

  1. Delphi Method Questionnaire Design:
     • Recruit 16 industry experts to rate the importance of items from existing questionnaires in two rounds.
     • Modify item wording to align with VR scenarios while ensuring consistency and clarity.
  2. Exploratory Factor Analysis (EFA):
     • Design a VR experiment (including 8 conditions: high/low combinations of fidelity dimensions) and conduct FPS testing with 55 participants.
     • Use EFA to validate the reliability and factor structure of the questionnaire, ultimately finalizing a 10-item questionnaire with three factors (interaction presence, scenario presence, display presence).
  3. Experiment Implementation and Scoring Standards Design:
     • Manipulate different fidelity dimensions during the experiment, with participants completing specific tasks and answering the FPS questionnaire.
     • Calculate total scores and sub-dimension scores to reveal the impact of different fidelity aspects of the system on presence.

Research Outcomes

• Specific Outcomes:

  • Established the Fidelity-based Presence Scale (FPS), consisting of 10 final items divided into three sub-dimensions (interaction presence, scenario presence, display presence).
  • Validated that FPS can significantly distinguish and evaluate the independent contributions of different fidelity dimensions to presence.

• Advantages Compared to Existing Solutions:

  • Clearly distinguishes the different impacts of interaction, scenario, and display fidelity on presence, offering more detailed analytical capabilities compared to traditional presence questionnaires (e.g., SUS, IPQ).
  • Expert consensus-driven design enhances the scientific rigor and consistency of the scale.
  • Provides an open-source questionnaire template (PDF, Word, Qualtrics formats) to facilitate researcher adoption and cross-study comparisons.

• Experimental or Evaluation Results:

  • High interaction fidelity (e.g., direct manipulation with virtual hands) significantly improved presence scores compared to low fidelity (e.g., ray-casting techniques).
  • High scenario fidelity (e.g., consistent gravity physics) also significantly enhanced participants' scenario presence.
  • High display fidelity (e.g., high-polygon models and background sound effects) showed a positive impact on presence in the experiment, though its effect was slightly weaker than other dimensions.

• Limitations and Future Directions:

  • Expert Sample Representativeness: Experts participating in the Delphi Method were primarily from North America and Europe, lacking global diversity.
  • Scope of Application Scenarios: FPS validation studies were limited to a single task and environment, requiring further validation across more tasks and scenarios.
  • Potential Impact of Avatars: The current experiment did not include the influence of virtual body avatars on presence; future research could explore the potential contributions of this interaction.
  • Task Complexity: Future studies could introduce more dimensions of variation (e.g., scene behavior or additional visual/auditory changes) to validate the broader applicability of FPS.

Conclusion

The development and validation of FPS provide an essential tool for measuring presence in VR research. By leveraging the system fidelity framework and expert consensus design, researchers and developers can gain clearer insights into the contributions of system components to user immersion and presence. This tool also paves the way for deeper research and application optimization in the future.