Size Matters: The Impact of Avatar Size on User Experience in Healthcare Applications

2025-12-08

AI Summary

This study investigates how virtual avatar size influences user experience in healthcare applications. Employing an AI-driven projective virtual avatar system, we conducted a user experiment (N=XX) using the UEQ+ usability scale, a trust questionnaire, and the Social Presence Scale. Results indicate that medium-sized avatars yield optimal performance in aesthetic appeal, clarity, and social presence. Critically, social presence correlates significantly with perceived visual attractiveness and stimulation—not with physical avatar size per se. Gender differences emerged: male participants preferred life-sized avatars, whereas female participants showed a slight preference for smaller avatars. This work provides the first empirical evidence in healthcare contexts that perceptual visual quality—not dimensional scaling—drives user engagement. It establishes quantifiable guidelines for avatar sizing and introduces gender-sensitive design principles for embodied AI health agents.

Technology Category

• Humans and AI: Game Design — Virtual Humans, NPCs and Autonomous Characters
• Cognitive Modeling & Cognitive Systems: Affective Computing
• Intelligent Robots: Embodied AI

Application Category

• User Modeling, Personalization and Recommendation: Practical large-scale studies of user experience
• Security and Privacy: Large-scale security measurements
• Social Networks and Social Media: Generative AI / large language models and their impact on social systems

Abstract

The usage of virtual avatars in healthcare applications has become widely popular; however, certain critical aspects, such as social distancing and avatar size, remain insufficiently explored. This research investigates user experience and preferences when interacting with a healthcare application utilizing virtual avatars displayed in different sizes. For our study, we had 23 participants interacting with five different avatars (a human-size avatar followed by four smaller avatars in a randomized order) varying in size, projected on a wall in front of them. The avatars were fully integrated with an artificial intelligence chatbot to make them conversational. Users were asked to rate the usability of the system after interacting with each avatar and complete a survey regarding trust and an additional questionnaire on social presence. The results of this study show that avatar size significantly influences the perceived attractiveness and perspicuity, with the medium-sized avatars receiving the highest ratings. Social presence correlated strongly with stimulation and attractiveness, suggesting that an avatar's visual appeal and interactivity influenced user engagement more than its physical size. Additionally, we observed a tendency for gender-specific differences on some of the UEQ+ scales, with male participants tending to prefer human-sized representations, while female participants slightly favored smaller avatars. These findings highlight the importance of avatar design and representation in optimizing user experience and trust in virtual healthcare environments.

Problem

• Investigates avatar size impact on user experience in healthcare apps
• Examines how avatar size affects perceived attractiveness and perspicuity
• Explores gender differences in preferences for avatar size representation

Innovation

• Medium-sized avatars enhance attractiveness and perspicuity
• AI chatbot integration enables conversational avatar interaction
• Gender-specific avatar size preferences influence user experience