From words to sentences: designing and evaluating a parent-facing sign language learning app.

To prevent language deprivation, hearing parents of deaf and hard of hearing (DHH) children need to learn sign language as soon as possible after their child is identified as DHH. However, sign language resources for parents are limited and often lack focus on sentence structure. To address these gaps, we have been developing ZINinNGT, a mobile Dutch Sign Language (NGT) learning app designed specifically for parents and focused on sentence formation. In this paper, we describe the app's initial design principles, report on feedback from hearing parents and NGT teachers on the ZINinNGT prototype, and present an updated set of design principles based on this feedback. Twenty-one hearing parents of DHH children and six NGT teachers participated in our study and individually tried the prototype while verbalizing their thoughts and actions. Participants responded positively to the app's sentence-based approach and appreciated features that accommodated different learning preferences, such as the adjustable playback speed and camera angle. Moreover, they appreciated that the content was applicable to the daily lives of parents with young children. At the same time, they expressed a desire for a more holistic, visual and child-friendly app. They wished for an app that supported both vocabulary learning and sentence construction, included little text, and could be used together with their child. Based on their feedback, we propose eight design principles for parent-facing sign language learning tools. Our findings suggest that a sentence-focused app can be a valuable complement to courses, addressing the need for more parent-oriented resources that go beyond vocabulary learning.