Gaze-tracking technologies can enable computer access for users who are unable to use standard input devices. However, using gaze as input poses challenges for interactions that require visual planning, like playing a digital instrument. We explore how multimodality can support eye-controlled musical expression by designing different multi-modal gaze interactions around a digital instrument we call Dueto. We tackle three design goals: creating an instrument that is explorable, easy to learn, and allows feature controllability. We showcase three different multimodal interactions for music playing such as eye gaze only, gaze + switch, and gaze + partner mode.

For eye tracking to become a ubiquitous part of our everyday interaction with computers, we first need to understand its limitations outside rigorously controlled labs, and develop robust applications that can be used by a broad range of users and in various environments. Toward this end, we collected eye tracking data from 80 people in a calibration-style task, using two different trackers in two lighting conditions. We found that accuracy and precision can vary between users and targets more than six-fold, and report on differences between lighting, trackers, and screen regions. We show how such data can be used to determine appropriate target sizes and to optimize the parameters of commonly used filters. We conclude with design recommendations and examples how our findings and methodology can inform the design of error-aware adaptive applications.

Augmentative and alternative communication (AAC) devices are a critical technology for people with disabilities that affect their speech. One challenge with AAC systems is their inability to portray aspects of nonverbal communication that typically accent, complement, regulate, or substitute for verbal speech. In this paper, we explore the design space of awareness displays that can supplement AAC devices, considering their output features and their effects on the perceptions of interlocutors. Through designing prototypes and getting feedback on our designs from people with ALS, their primary caregivers, and other communication partners, we consider (1) the consistent tensions that arose between abstractness and clarity in meaning for these designs and (2) the ways in which these designs can further mark users as "other." Overall, we contribute a generative understanding of designing AAC awareness displays to augment and contextualize communication.

Current eye-tracking input systems for people with ALS or other motor impairments are expensive, not robust under sunlight, and require frequent re-calibration and substantial, relatively immobile setups. Eye-gaze transfer (e-tran) boards, a low-tech alternative, are challenging to master and offer slow communication rates. To mitigate the drawbacks of these two status quo approaches, we created GazeSpeak, an eye gesture communication system that runs on a smartphone, and is designed to be low-cost, robust, portable, and easy-to-learn, with a higher communication bandwidth than an e-tran board. GazeSpeak can interpret eye gestures in real time, decode these gestures into predicted utterances, and facilitate communication, with different user interfaces for speakers and interpreters. Our evaluations demonstrate that GazeSpeak is robust, has good user satisfaction, and provides a speed improvement with respect to an e-tran board; we also identify avenues for further improvement to low-cost, low-effort gaze-based communication technologies.