Results

This section presents feedback on the ZINinNGT prototype from two groups: (1) hearing parents of DHH children learning NGT or Sign-supported Dutch (NmG), and (2) teachers who teach NGT courses for parents. The feedback is organized into four key categories: (1) user interface, (2) content, (3) scope, and (4) intended use—the latter referring to participants’ responses to the question of whether they would use the app once it becomes available.

In this analysis, parents learning NGT and those learning NmG are treated as a single group. This decision was based on the difficulty of reliably distinguishing between the two, as NmG can be considered lying on a continuum between Dutch and NGT. Moreover, many parents attended courses described as NmG blended with elements of NGT. While one might expect that learning NmG versus NGT could influence feedback on an app specifically aimed at NGT learning, making a clear distinction between these subgroups was unfortunately not possible.

User interface

Feedback on the prototype’s interface was extensive and generally positive. For clarity, the findings are organized into three subsections: (1) search bar and filters, (2) viewing videos, and (3) home screen and app navigation.

Search bar and filters

Parents generally appreciated the search tools, particularly the inclusion of the search bar (N = 6)¹ and the semantic theme filter (N = 7), which helped them quickly find sentences relevant to their child or daily routines. However, several parents did not understand the purpose of the grammar filter, as it was unclear what selecting this filter resulted in.

Teachers mostly appreciated the favorite filter (N = 3) as this would allow parents to save difficult sentences they wanted to practice and easily retrieve them later.

Viewing videos

The prototype’s most frequently valued feature among parents was the camera angle tool (N = 12), which allowed users to switch between a front, left, and right camera view. Although this feature was new to most parents, many appreciated that it made viewing the signs easier, especially the signs’ handshape—something they often found difficult to see in other materials with only a front camera.

Another highly valued feature was the ability to adjust the playback speed (N = 11). Parents mentioned that they often found signing to be very fast, and therefore they appreciated the possibility to slow down the videos without them getting blurry or choppy. The literal sign-for-sign translation with highlighting was also appreciated (N = 11), as this provided insight into the sentence structure and sign order. A mother (M) and a father (F) who tested the prototype together explained:**M: “**And you actually also see the grammatical structure of NGT, because you can read along underneath. That’s actually nice, too. We often do that out loud in class now.”[…]F: “That’s not the case with the other apps, right?”M: “No.”F: “Then you just get the sentence, and then it’s produced, and then you have to parse it all by yourself.”[…]F: “But this is really nice. With this, I’m completely… Because when I see name of teacher do it, she goes really fast. And then you’re watching the signs, and you’re…”M: “Parsing.”F: “Parsing the sentence. And this is… This really helps a lot.”

Besides the literal sign-for-sign subtitles, parents valued the option to choose between subtitle types (N = 8): sign-for-sign translation, sentence-level subtitles or no subtitles. Parents considered being able to switch the subtitles off as helpful, as they viewed this option as a way to test themselves by checking if they could understand the signing without seeing the translation.

Many of the comments made by parents about the user interface were also mentioned by the teachers in our sample. Teachers also mostly valued the different playback speeds (N = 5), different camera angles (N = 3), literal sign-for-sign translation (N = 2) and the general subtitle tool (N = 2).

Home screen and app navigation

Participants also commented on the overall layout of the app. While parents considered the prototype to have a clear overview, several parents (N = 5) and teachers (N = 2) found the home screen layout surprising or unintuitive, as they expected to first see a menu (e.g., with tiles or themes), rather than being immediately presented with a list of written sentences.

Several additional usability issues became apparent during testing. Although the information button was intended to link each sentence to its grammar explanation video—an important feature for the grammar-aware input—most participants either overlooked it or assumed it contained general app information, such as privacy policies, and dismissed it.

Two Deaf teachers further commented on the text-heavy design of the prototype, stating that a sign language app should be more visually oriented. They mentioned that because NGT is a visual language, an app should reflect this visual nature. In addition, the teachers noted that some parents come from multilingual backgrounds and may not have strong Dutch reading skills. Including too much Dutch text could therefore make the app less accessible for these parents. As one teacher explains:“There’s a lot of text in it. […] There’s a strong emphasis on Dutch, and that really demands strong Dutch language skills. And of course, there’s a group of people who aren’t digitally literate. And for them, this app is poor or even not accessible at all. […] It’s not visual, whereas you’d want NGT to be presented as a visual language. And that’s not happening here.”

Content

Many parents highlighted the app’s focus beyond vocabulary as a major strength, particularly compared to other apps or course materials. Twelve parents appreciated the inclusion of full sentences, and nine specifically valued the grammar explanation videos.² Some parents specifically named the transition from isolated signs to sentences as particularly difficult in learning NGT, and therefore, they appreciated the app as a way to get a feel for NGT grammar and sentence structure. One parent explains about the app extending beyond the vocabulary level:“We really just missed this, exactly this, because you can’t find this anywhere. […] That’s just because my experience with apps for NGT or NmG or whatever, or courses or… Yeah, it was always just really limited: words, words, words.”

Parents further appreciated that the app content was relevant to young children and their daily lives (N = 10). They mentioned that the included sentences were sentences they frequently used with their children, making the content directly applicable in their everyday interactions.

Another topic that frequently emerged during testing was that the signers in the videos often deviated from standardized signs and syntactic structures typically taught in parental courses (N = 9). While most parents simply noted that they had learned certain signs differently, some parents saw this as a drawback, expressing a strong preference for the use of standardized signs. During one session where the participant’s child was also present, the child began copying a sign from the prototype, but the parent stopped her, explaining that it was not the correct sign—that is, not the standard sign.

Several parents also drew conclusions about the correctness of signs they had previously learned, adjusting their signing based on the sign variants included in the prototype, assuming they had misremembered the course signs. For others, these differences caused confusion, as they were unsure whether the sign produced in the video or the one learned during their course was the “correct” version.

Teachers’ feedback on the content mostly concerned the correctness and quality of the signing and translations. Five out of the six teachers commented on signs or syntax that they would produce differently during their own lessons. This topic about correctness or standard language use often took up a considerable part of the sessions with teachers. While some did not view these differences as something negative per se, others expressed a clear preference for the use of standardized signs and syntax as used during their own lessons or as described in teacher guidelines:“Grandmother, oh, again a different sign. grandmother [copies the prototype’s sign for grandmother], I didn’t know that one either. I know grandmother [signs the standardized sign for grandmother], but grandmother [copies the prototype’s sign again], okay. Yeah, no, I would then… Both can be there, but I would also include the standardized one. That helps avoid frustration for parents, I think.”“[signs] This is how I would sign it grammatically. And the sign for ‘ball’, I would sign it differently. But should that be a concern? Yeah, I don’t know. I follow what’s on the Dutch Sign Center website.³ And if parents do homework at home and look this up, and if I then use a different sign than what they might see, that could be confusing.”

Teachers also frequently commented on the correctness of the sign-for-sign translation (N = 5). Teachers commented on elements missing in the translation as well as elements they considered incorrect. Most teachers interpreted this translation as a gloss, which led some to comment on the absence of standard glossing conventions—such as the use of small caps.

Positive feedback highlighted that the content was appropriate for children and included child-directed signing (N = 2). Teachers noted as an advantage that some sentences reflected language suitable for younger children, while others were more suited to slightly older children. Similar to the parents, teachers also valued that the prototype included full sentences and thus extended beyond vocabulary (N = 2).

Scope of the app

While parents appreciated that the prototype went beyond vocabulary, many parents expressed surprise that it did not include separate vocabulary at all (N = 8). While some parents only expressed surprise at not seeing vocabulary, others considered this a disadvantage, as it made the prototype less holistic. They felt they would need to use an additional app or tool to look up individual signs. One parent explained:“The only thing is, you think, yeah, you’re in this app because you want to look something up. And then you don’t want… Shall we make a nice card for grandma?, it says here. And then, of course, more content will be added. But then if you want to say Shall we make a nice card for Uncle Piet?, then you think, oh shoot, what’s the sign for uncle? Yeah, that’s something you can’t quickly look up then.”

Five parents, therefore, suggested adding vocabulary to the app. In addition, six parents proposed including quizzes to test and challenge themselves. Several also mentioned appreciating how some other materials make signs’ handshapes more explicit—for example, through an icon next to the video depicting the correct handshape or by a short demonstration of the handshape before producing the sign itself. Because handshapes are often difficult to see, parents expressed a wish to include such features in the app as well.

Beyond quizzes, some parents expressed that they missed a broader form of gamification (N = 5), such as the ability to compete against other users, the addition of motivational elements, or the addition of fun games within the app.

Similar to the parents, teachers expressed a desire for separate vocabulary, quizzes, and explicit handshape information (each mentioned in two interviews). They explained that quizzes would help parents practice and reinforce what they had learned. Information on handshapes was also valued, as handshapes are often challenging for parents and usually receive extra attention in class. Teachers also emphasized the importance of making the app more accessible to parents with different language backgrounds who are not proficient in written Dutch, suggesting the inclusion of translations into other languages such as Arabic or Turkish (N = 2). Finally, two teachers indicated that they would like the subtitles to be interactive, allowing parents to click on individual words to view videos of isolated signs, related vocabulary, or sign variants.

User intent

Parents with children within the target age group (1–5 years) were asked whether they would use ZINinNGT if it became available with the same design but more content. Parents with older children were asked whether they would have used the app when their child was still younger. Teachers were asked whether they considered the app useful for parents.

Eighteen of the twenty-one parents indicated that they would use ZINinNGT, citing the following main reasons:ZINinNGT fills a gap in current sign language learning materials by offering more than just vocabulary;It is easily accessible on a mobile phone and does not require logging in;The content is highly relevant to parents with young children;There is a general lack of available sign language learning materials, so any new resource is very welcome.

Parents mentioned various moments and goals for which they would use the app. Some said they would use it as an on-the-spot translation tool during daily interactions with their child. Others indicated they would use it to prepare for specific situations, for example, by going through the theme “animals” before visiting the zoo with their child. Most parents, however, mentioned wanting to use the app as a learning tool during spare moments. Although the app was not designed to be attractive to children, some parents also said they would like to use it together with their child as a shared activity or for joint learning, indicating a large wish for material that can be used together by parent and child.

Among teachers, four of six considered the app useful for parents. One teacher felt unable to judge its usefulness but would inform parents once it became available, while another noted it would be useful provided it also included separate vocabulary. Teachers’ reasons largely aligned with those of parents: they valued the inclusion of full sentences and grammar explanation, as well as the app’s practical and parent-focused nature, and they also mentioned the general lack of NGT learning materials. One teacher emphasized that most parents are eager to make use of any available sign language material.

Footnotes

1. Throughout this paper, N refers to the number of sessions in which a comment was made, not the number of individual participants (as one session involved two parents). For the parents, total N = 20, and for teachers, N = 6. ↩

2. Note that grammar explanation videos were not included in the prototype yet; parents could only see placeholder videos and some of the potential topics. ↩

3. The Dutch Sign Center website refers to the online NGT dictionary [38], which includes the standardized signs as described in Sect. 3.2.3. ↩