Virtual Urban Field Studies: Evaluating Urban Interaction Design Using Context-Based Interface Prototypes

TL;DR

This paper addresses the challenge of safely and affordably testing urban AV–pedestrian interaction by introducing Virtual Urban Field Studies (VUFS), a context-based interface prototyping approach that uses 360-degree video and ambisonic audio to create realistic virtual environments. It validates verisimilitude through psychometrically grounded presence measures and demonstrates, via a mixed-methods study with para-authentic vehicle sounds, that high physical presence can be achieved without costly higher-order ambisonics. The study provides design guidelines for immersion and sound design in VUFS and shows that para-authentic auditory stimuli can evoke authentic user responses, supporting VUFS as a practical alternative to real-world field trials. Overall, VUFS offers a scalable, safe, and ecologically valid method for evaluating urban interaction designs, with implications for accelerating development and testing of AV interfaces in shared urban spaces.

Abstract

In this study, we propose the use of virtual urban field studies (VUFS) through context-based interface prototypes for evaluating the interaction design of auditory interfaces. Virtual field tests use mixed-reality technologies to combine the fidelity of real-world testing with the affordability and speed of testing in the lab. In this paper, we apply this concept to rapidly test sound designs for autonomous vehicle (AV)--pedestrian interaction with a high degree of realism and fidelity. We also propose the use of psychometrically validated measures of presence in validating the verisimilitude of VUFS. Using mixed qualitative and quantitative methods, we analysed users' perceptions of presence in our VUFS prototype and the relationship to our prototype's effectiveness. We also examined the use of higher-order ambisonic spatialised audio and its impact on presence. Our results provide insights into how VUFS can be designed to facilitate presence as well as design guidelines for how this can be leveraged.

Figures (5)

• Figure 1: The autonomous vehicle during technical testing, having navigated through a shared space and come to a stop. The scenario is being recorded by a 360-degree video camera and spatial microphone to create an immersive virtual environment for a Virtual Urban Field Study.
• Figure 2: The camera and microphone setup used for capturing 360-degree video and spatial audio, illustrating the equipment configuration and arrangement for creating immersive virtual environments used in Virtual Urban Field Studies.
• Figure 3: Screenshot of the 360-degree video recording from a user's perspective in virtual reality (left). The panel interface enabling a user to select their prediction for the behaviour of the autonomous vehicle (right).
• Figure 4: Visualisation of the responses for the Multimodal Presence Scale and additional audio questions, illustrating the levels of agreement among participants. These charts provide insights into the various dimensions of presence experienced by users during the study, highlighting particularly high physical presence.
• Figure 5: Comparison of mean presence ratings from the Multimodal Presence Scale (MPS) subscales and additional audio questions for the experimental group. This shows no significant difference between the conditions, which indicates that the para-authentic stimuli in the virtual environment did not degrade users' feelings of presence, demonstrating their potential as ecologically valid platforms for Virtual Urban Field Studies.