Extending Interaction Fidelity: The Impact of Feedback Symmetry on the Usability of Mixed Reality Applications

This paper introduces an extension to the Framework for Interaction Fidelity Analysis (FIFA) that incorporates a new dimension called Feedback Symmetry. While FIFA effectively evaluates how closely Mixed Reality (MR) interaction techniques resemble their real-world counterparts in terms of biomechanical and control aspects, it does not fully account for the role of output feedback in user experience and performance. By adding Feedback Symmetry, a measure capturing the timeliness, accuracy, and realism of system responses, we shift from focusing solely on input fidelity toward a holistic, bidirectional assessment of MR interactions. Utilizing this extended framework to analyze previously published experimental data reveals improved alignment between predicted fidelity scores and observed user performance compared to the original framework. In particular, conditions previously rated as high in fidelity but performing poorly in practice become more accurately represented when feedback properties are considered. This approach clarifies why certain natural yet inconsistent feedback schemes impede usability, while simpler yet consistent cues can enhance user outcomes. Our results highlight the importance of balanced feedback design and suggest that incorporating Feedback Symmetry into FIFA can guide researchers and developers in refining their interaction techniques, ultimately improving the usability and effectiveness of MR applications.