Aligner, Nodder, and Winker : Creating Complete, Hands-Free Interaction Techniques that Unify Precise, UI-Independent Selection and Dragging ETRA016

Hou, Baosheng James and Manakhov, Pavel and Hu, Jinghui and Wang, Haopeng and Gellersen, Hans (2026) Aligner, Nodder, and Winker : Creating Complete, Hands-Free Interaction Techniques that Unify Precise, UI-Independent Selection and Dragging ETRA016. Proceedings of the ACM on Human-Computer Interaction - CSCW, 10 (3). pp. 1-21. ISSN 2573-0142

Abstract

Hands-free interaction is essential when users’ hands are occupied with primary tasks. A key challenge is unifying precise, UI-independent selection and continuous dragging without explicit mode switching. This paper introduces two novel techniques: Aligner (spatial eye-head alignment) and Nodder (gestural decomposition of a nod); and evaluates them against an established Winker technique, a gestural clutch using single-eye closure. A user study with controlled Fitts’ law and dragging tasks, alongside a practical application, evaluated the techniques. Results show that Aligner offers superior selection precision but creates a visuomotor conflict during dragging; Nodder optimizes movement efficiency for large-amplitude targets despite higher physical effort; and Winker provides the fastest performance but is susceptible to accidental activation. These findings inform the design of future hands-free systems by highlighting the context-dependent nature of this interaction challenge.