## 4 Discussion
Regarding the research setting, most of the research is conducted in a school and laboratory, and two studies are in the community environment, while some studies do not mention the setting. To a certain extent, the social skills of autistic children and adolescents may be improved with training in a laboratory setting, but their core issue (social) still needs to be practiced in a real social environment. The ultimate goal of the intervention is to integrate them into society and family, while there is no family environment mentioned. It should be emphasized that school and institutional research settings are very important because there has peer participation. However, special education teachers can only accompany autistic children for a few years, and they will eventually return to their families and enter society. Future research can involve more family interventions, enable parents to participate more and guide their children to live an active life. More family environments can involve and enable parents to participate more and be their mentors. The analysis results of the MAR durability effects showed that most of the studies conducted their research without the far effects of AR, which may be due to the limitation of research time. Part of the articles studied the durability effects of MAR in a short period (up to 9 weeks), while other articles focusing on long-term effect research have reported half a year to one year. It is almost a blank area. Research on generalization and maintenance is still in the infant stage. The long-term effect and generalization of mobile augmented reality can push the evidence-based practical research on mobile augmented reality further. The application of learned skills to other environments, such as expressing greetings learned in the lab to strangers in society which is also a major issue for persons with ASD. However, like every other review, this paper has some limitations such as the keywords, inclusion and exclusion criteria we chose contain subjective elements, which might affect the number of selected primary studies. Furthermore, regarding the studies we reviewed, we can summarize the major problems and limitations faced by the studies. Small sample;  
Research design issues;  
Not generalizable results;  
Short intervention time;  
Participants are not differentiated by age;  
No use of control groups;  
Difficult in recruiting participants;  
Lack of gender parity of the sample;  
App design issues;  
Internet connection issues. Many of the existing mobile AR applications for people with ASD are not considered very practical due to insufficient functionality. Designers must focus on users and design products that have high interactivity, quality and meet user needs to improve user satisfaction and make mobile AR become widely accepted. As for the issue of internet connection, which is a considerable indicator in most mobile AR-related user experience studies, the solutions can be focused on the selection of mobile devices and intervention locations. Furthermore, the studies on internet stability and speed, especially in a rural area, are still in the infant stage, and more effort should be put into this particular area. The main issue related to the evaluation of mobile AR in people with ASD may point to the research design method, sample and the intervention period. Currently, there is no research report on randomized experiments in this field; thus, the effectiveness of randomized experiments research design still needs to be investigated. The most mentioned in the studies are the small sample size and short intervention time. The determination of the participants' number is related to the research design method, region, and many other factors. Recruiting more participants, establishing inclusion criteria and conducting strict screening can improve the accuracy of the research. The distribution of participants between females and males reveals an extremely limited gender bias, and more female autistic participants can be recruited to solve this issue.