When motivation can be more than a message: designing agents to boost physical activity

TL;DR

This study investigates how virtual agents in physical activity interventions can be perceived as co-participants exerting effort, emphasizing the importance of authenticity and social cues to enhance user motivation and engagement.

Contribution

It introduces design principles for virtual agents to appear more authentic and socially engaging by demonstrating effort and relatable benchmarks, improving motivation in physical activity support.

Findings

Perceived effort and authenticity influence user trust and motivation.

Social features are valued when users believe others are genuinely trying.

Ambiguous activity levels can undermine trust and engagement.

Abstract

Virtual agents are commonly used in physical activity interventions to support behavior change, often taking the role of coaches that deliver encouragement and feedback. While effective for compliance, this role typically lacks relational depth. This pilot study explores how such agents might be perceived not just as instructors, but as co-participants: entities that appear to exert effort alongside users. Drawing on thematic analysis of semi-structured interviews with 12 participants from a prior physical activity intervention, we examine how users interpret and evaluate agent effort in social comparison contexts. Our findings reveal a recurring tension between perceived performance and authenticity. Participants valued social features when they believed others were genuinely trying. In contrast, ambiguous or implausible activity levels undermined trust and motivation. Many participants expressed skepticism toward virtual agents unless their actions reflected visible effort or were grounded in relatable human benchmarks. Based on these insights, we propose early design directions for fostering co-experienced exertion in agents, including behavioral cues, narrative grounding, and personalized performance. These insights contribute to the design of more engaging, socially resonant agents capable of supporting co-experienced physical activity.