Standardized Inquiry Instruments for Usability Assessment in Digital Health Applications Featuring Embodied Communication Agents: A Scoping Review

This scoping review aims to map and synthesize the current evidence on usability assessment using inquiry instruments (i.e., standardized scales for systematically collecting users’ self-reported evaluations of systems’ usability) in digital health applications featuring Embodied Communication Agents (ECAs) defined as virtual agents with a perceivable embodiment (e.g., virtual avatars, animated characters, or physical robots) that engage users through multimodal communicative behaviors. The review follows the PRISMA-ScR guidelines and covers literature published until the beginning of 2026 in English. It includes peer-reviewed usability assessment empirical studies of digital health applications supported on ECA. Expected outcomes include: • A comprehensive mapping of available ECA technologies for digital health applications. • Identification of normalized inquiry instruments used to collect users’ self-reported evaluations of systems’ usability. • Insights to inform the usability assessment of innovative ECA systems. • Recommendations for future usability assessments of ECA-based digital health applications. This work will contribute to the field of digital health, aiming to improve usability assessment of applications supported on ECA.