Examining Humanness as a Metaphor to Design Voice User Interfaces

TL;DR

This study investigates how human and non-human metaphors in voice user interfaces affect user perceptions and engagement, revealing context-dependent preferences and the influence of metaphor awareness on adoption intentions.

Contribution

It introduces an empirical comparison of human versus non-human metaphors in VUI design across health and finance domains, highlighting context-specific effects and design considerations.

Findings

Users prefer human metaphors in health contexts for enjoyability.

No significant perception difference in finance between metaphors.

Awareness of metaphor use influences user adoption preferences.

Abstract

Voice User Interfaces (VUIs) increasingly leverage 'humanness' as a foundational design metaphor, adopting roles like 'assistants,' 'teachers,' and 'secretaries' to foster natural interactions. Yet, this approach can sometimes misalign user trust and reinforce societal stereotypes, leading to socio-technical challenges that might impede long-term engagement. This paper explores an alternative approach to navigate these challenges-incorporating non-human metaphors in VUI design. We report on a study with 240 participants examining the effects of human versus non-human metaphors on user perceptions within health and finance domains. Results indicate a preference for the human metaphor (doctor) over the non-human (health encyclopedia) in health contexts for its perceived enjoyability and likeability. In finance, however, user perceptions do not significantly differ between human (financial advisor) and non-human (calculator) metaphors. Importantly, our research reveals that the explicit awareness of a metaphor's use influences adoption intentions, with a marked preference for non-human metaphors when their metaphorical nature is not disclosed. These findings highlight context-specific conversation design strategies required in integrating non-human metaphors into VUI design, suggesting tradeoffs and design considerations that could enhance user engagement and adoption.