CareHub: Smart Screen VUI and Home Appliances Control for Older Adults
Ningjing Sun · 2020 · Proceedings of the 22nd International ACM SIGACCESS Conference on Computers and Accessibility (ASSETS 2020) · doi:10.1145/3373625.3418051
Summary
This demonstration paper presents CareHub, a smart screen prototype that augments voice user interfaces (VUIs) with complementary visual output to help older adults control home appliances more effectively. The research was conducted at the Rhode Island School of Design and involved two preliminary studies with six Chinese older adults (aged 79-89, mean 83.67) living independently in cities. The first study was a contextual inquiry in participants' homes observing their challenges with traditional appliance controls (buttons, remote controllers). The second was a lab-based usability test where participants interacted with three Chinese-language voice assistants — Xiaodu (smart screen), Xiao'ai (smart speaker), and Siri (smartphone) — to complete tasks like playing songs and setting alarms. The findings informed the design of CareHub, which addresses specific usability problems at each VUI interaction state: idle, listening, processing, error, and confirmation. The prototype was evaluated using a Wizard of Oz approach with animated scenarios, achieving a System Usability Scale score of 83.75 (top 10% of scores), indicating high acceptance despite participants' unfamiliarity with voice technology — five of six had never heard of VUIs before the study.
Key findings
The preliminary studies revealed five key challenges older adults face with VUIs and smart home control: confusion about appliance modes and menu structures ("it has too many buttons"), safety concerns and lack of confidence in controlling appliances properly, the need for context-aware proactive behaviour from devices (e.g., reminders to turn off lights or bring an umbrella), a strong preference for smart screens over smart speakers or phones due to the ephemeral nature of voice-only output putting too much burden on working memory, and low trust in voice technology as a novel and unfamiliar interaction method. CareHub addresses these through three design innovations: (1) visual time-out cues that show a countdown when the user pauses mid-thought, reminding them to finish their command before the system stops listening; (2) error recovery strategies that provide clear explanations of what went wrong, why, and visual alternatives — for example, showing available programs when a requested TV show hasn't started; and (3) instant visual confirmatory feedback showing the real-world effect of commands (e.g., a visual representation of lights dimming), which was especially valued when users were in a different room from the controlled appliance. Participants rated time-out cues and confirmatory feedback particularly highly.
Relevance
This research highlights a critical gap in smart home accessibility: voice interfaces designed for mainstream users create significant barriers for older adults, who are precisely the population that could benefit most from hands-free home control for aging in place. For accessibility practitioners, the key insight is that voice-only interfaces are insufficient — multimodal output combining voice with visual feedback dramatically improves usability, trust, and error recovery. The systematic analysis of VUI states (idle, listening, processing, error, confirmation) with corresponding usability issues and improvements provides a practical framework for designing more accessible voice interactions for any user group. The finding that older adults prefer smart screens over voice-only speakers challenges the assumption that simpler (fewer modalities) is always better for aging users. The study's limitations are notable — all six participants were older adults without disabilities living independently — suggesting that challenges would be even greater for users with cognitive, sensory, or motor impairments. The work connects to broader aging-in-place goals where accessible smart home technology could extend independent living.
Tags: voice user interface · older adults · smart home · aging in place · multimodal interaction · usability · error recovery · home appliances