Related work

Existing sign language learning apps for parents

In the Netherlands, two popular sign language learning apps have been developed specifically for DHH children,¹ and these are also frequently used by hearing parents—often as a shared activity with their children—to learn child-related NGT vocabulary [16]. Both apps focus on vocabulary learning through play and are designed to appeal to young children by incorporating games, engaging images and colors, and, in the case of the KinderGebaren app, videos of children demonstrating the signs [18, 19].

Outside of the Netherlands, several initiatives have focused on developing sign language learning apps. Here, we describe some that are particularly relevant to ZINinNGT because they are either intended for hearing parents of DHH children or because they extend beyond the vocabulary level by providing sentences and grammar explanations. Examples of sign language learning apps aimed at hearing parents include SMARTSign and PopSign for ASL, and NextSense Auslan Tutor for Australian Sign Language (Auslan) [20–22]. Auslan Tutor is designed for parents learning Auslan and focuses on vocabulary learning, with key signs divided into semantic themes. It includes features such as quizzes, adjustable playback speed, and multiple camera angles that allow users to slide around the signer. It also provides linguistic information such as handshape information, sign variants, and example sentences showing sign use.

PopSign is a bubble-shooter game aimed at hearing parents of DHH children that draws on vocabulary from the MacArthur-Bates Communicative Development Inventories [23], a set of vocabulary inventories that includes concepts typically acquired early in children’s language development. PopSign supports both receptive and expressive ASL vocabulary development by making use of sign recognition [24]. SMARTSign is another vocabulary-focused ASL app designed to help hearing parents of DHH children learn and practice signs. It features a search function, quizzes, and a practice component that allows parents to record and watch videos of themselves signing. Future development plans include expanding the app to incorporate ASL grammar as well [20].

Several commercial sign language apps have also been developed, though these are often aimed at a general audience rather than specifically at hearing parents. Toleio is a gamified app for Norwegian Sign Language that includes a dictionary, quizzes, simple sentences and dialogues, as well as modules on grammar and Deaf² culture and history [25]. Although Toleio does mention ‘parents and children’ among their target groups, its content is designed for a more general audience, as it does not seem to include content specifically tailored to hearing parents of DHH children. The company behind Toleio, SignLab, also created very similar apps for other sign languages, including ASL Bloom for ASL, yoDGS for German Sign Language, and ISL Journey for Indian Sign Language [26].

Lingvano supports ASL, British Sign Language, and Austrian Sign Language [27]. It is also highly gamified, featuring quizzes, rewards, and the possibility to set learning goals. In addition, it offers dictionary searches, example sentences and conversations, and grammar explanations. Lastly, PocketSign is a gamified app for ASL that includes lessons on vocabulary, simple phrases, and ASL grammar. It also tracks users’ learning progress, gives rewards, and features a dictionary and quizzes, including both sign comprehension and sign production quizzes that provide feedback based on sign recognition [28].

In sum, both within the Netherlands and internationally, a range of promising initiatives have been developed to support hearing parents of DHH children in learning sign language. These tools often incorporate engaging and innovative features (such as games, quizzes, multiple camera angles, and sign recognition) which make them attractive and accessible for families. However, despite their strengths, most existing apps remain limited to vocabulary learning, offering little support for developing sentence-level skills. Some apps do address sentence formation, but they target a broad audience and are not tailored to child-focused communication. This highlights the need for next-generation tools that specifically support parents and go beyond individual signs to foster broader communicative competence in sign language. Table 1 provides an overview of the apps and their features mentioned in this subsection, highlighting parent-focused content and support beyond vocabulary learning.

 | Tailored to parents/children | Beyond vocabulary
Lotte en Max Kindergebaren app | ✓ | ✘
KinderGebaren-app | ✓ | ✘
Auslan Tutor | ✓ | ✓a
PopSign | ✓ | ✘
SMARTSign | ✓ | ✘
Toleio | ✘ | ✓
Lingvano | ✘ | ✓
PocketSign | ✘ | ✓

Design principles for language learning apps

Jamaldeen et al. [29] conducted a study similar to the present study, in which they present a set of guidelines for designing mobile language learning applications. These guidelines are derived from principles identified in the literature and expanded with insights from their evaluation study of an English learning app they developed. The authors distinguish between technological, pedagogical, and human-centered facets of mobile learning design. For the purposes of this paper, we focus on the pedagogical and human-centered facets they identified, as these are most relevant to our work.

The pedagogical principles identified in their literature review include ‘keeping information organized’, which involves presenting content in a structured way and chunking and grouping of information, and ‘multiple pedagogy/activities’, which refers to accommodating different learning styles and incorporating diverse exercises to keep the learning interactive. Interactivity is an important feature of language learning apps, as it helps sustain learner engagement and supports learning retention [30].

For the human-centered facets, the authors in [29] highlight the design principles of ‘design for personalized learning’ and ‘incorporate collaborative activities’. Personalization entails tailoring the learning experience to the unique needs and preferences of individual learners [30]. According to the authors, this can, for example, be achieved by adding a bookmark function to allow users to organize lessons according to their preferences. Other approaches to personalization include the use of learning algorithms, which automatically adapt the difficulty of learning exercises based on users’ performance, or the adaptation of content based on users’ areas of interest (which users are sometimes asked about when creating an account) [30]. Collaborative activities can, for example, be supported through the integration of social media-based platforms and online forums. Through these platforms, learners can interact with one another as well as with teachers or native users of the target language [30].

Based on findings from their own evaluation study, the authors in [29] additionally propose ‘design for learner motivation’ as a human-centered design principle, which can be supported through game-based learning and by providing users with information about their learning progress. Several studies on mobile assisted-language learning applications also emphasize the importance of including gamification—implementing game elements in non-game contexts—to increase learning motivation and commitment [30, 31]. Examples of gamification elements that have been found to be positively perceived include rewards, badges, learning streaks, and leader boards, which create a sense of competition [31]. Lastly, the authors also add ‘design for supporting medium of learning’ to the pedagogical principles, concluding that mobile learning apps are most beneficial when used within a blended learning environment (combining mobile and e-learning with face-to-face courses) rather than as a primary means of learning.

To summarize, Table 2 presents the design principles described in this subsection.

Category | Design principle
Pedagogical | Keep information organized
Multiple pedagogies/activities
Design for supporting medium of learning
Human-centered | Design for personalized learning
Incorporate collaborative activities
Design for learner motivation

Footnotes

1. These are the KinderGebaren-app [18] and the Lotte en Max Kindergebaren app [19]. ↩

2. In this paper, ‘deaf’ with a lowercase d refers solely to audiological status, while ‘Deaf’ with an uppercase D refers to the cultural and linguistic minority group that uses sign language. ↩