# Accessibility in Native Mobile Applications for Users with Disabilities: A Scoping Review
## 5 Discussion  
This review used the PRISMA-ScR method to improve its quality and clarity by avoiding bias. This process allows three-step filtering to guide the reviewers. Additionally, the PRISMA-ScR includes a checklist (see Appendix A) to improve the quality of this review. In this review, most authors argue that (1) a mobile application can be accessible when incorporating elements that allow easy and intuitive interaction with physical or logical controls; for this, it is essential to incorporate bidirectional voice communication. (2) If the application contains video communication, the playback, transmission, and recording quality must include subtitles for the hearing impaired. (3) Audio description on videos is essential for visually impaired users. (4) It is necessary to include some software access to support products and authoring tools. Finally, the authors suggest designing accessible and inclusive mobile applications; the WCAG 2.1 [4] should be applied, containing guidelines grouped into four principles: perceivable, operable, understandable, and robust. Each guideline includes conformance criteria, which can be tested according to the three levels A, AA, and AAA, with level AAA being the highest level of accessibility. In this research, consideration was repaid to preferring the most used and adapted search strings according to each database's query structure. To reduce this limitation, we apply the PICO criteria to our search strings [9]. The choice of the five ACM Digital Library databases, IEEE Xplore, ScienceDirect, Scopus, and WOS, is sufficient because 32 of 211 scientific articles were duplicated, which implies that the coverage of the databases is high, so much so that some of them could have been excluded. However, the primary research search terms, such as accessibility and mobile applications, are traditional, well-defined, and accepted terms, reducing neglected research. In addition, because the research is focused on finding primary research on accessibility and mobile apps, there is less concern about capturing preliminary domain-related research. Likewise, when searching for some scoping review studies, we found that most of them focus on evaluating the usability of applications or how they are applied in various domains [40]. However, they are not concerned with evaluating the accessibility of native mobile applications considering the users' disabilities. Regarding accessibility in mobile applications associated with disability, we found that the most significant number of  
Figure 6: Keywords and answers to the research questions satisfied by the 22 primary studies extracted. primary studies refer to the sensory disability with 86.4%, including visual and hearing disability, followed by cognitive disability with 9.1%. We found very few studies, around 4.5%, referring to motor disability. The most used method for assessing accessibility in mobile applications according to disability is manual, with 50% of the studies extracted. Automatic review and heuristics achieve 18.2% of the extracted studies, while the combined method is little used, representing 13.6%. According to several authors [41], it is the most recommended because there are accessibility barriers that automatic review tools cannot detect. In the future, the great challenge for accessibility experts is to design an automatic evaluation tool that incorporates [6] artificial intelligence algorithms. The statistics of this study correlate with the proposals to improve accessibility according to the type of disability in mobile applications; the scoping review revealed that 63.6% apply WCAG 2.0 and 2.1 [4] because they provide a better level of accessibility and allow anticipating future regulatory changes. The selected studies revealed that the education sector has the highest number of accessible mobile applications with 21.6%, followed by banking, communication, services, and social media.