## 6 Limitations and Future Research  
As usual with studies that are based on surveys, the thoughts of the participants may be different than their actual skills and behavior. Additionally, the participants express their perceptions at a given moment so they may have different expressions at a different moment. So, there is a need for longitudinal studies with regard to teachers' perceptions and behavior. In addition, the limited sample was not representative of all teachers worldwide. Future research may investigate larger samples worldwide or in specific countries, educational levels, and subjects. Another limitation of the study is that it did not consider the technology infrastructure where participating teachers work with, a factor that can affect their views towards the use of AR. Moreover, the distribution of the participants by country and teaching subject was somehow irregular. Future studies should take these limitations into consideration. Studies that correlate teachers' attitudes and beliefs with respect to the development level of countries and/or technical infrastructure might provide further insights.  
This study investigated the teachers' perceptions with regard to ARinE. Future research may further analyze each one of the topics of this study. For example, it can scrutinize the teachers' required specific technical, pedagogical, and soft skills so that they can effectively apply ARinE in their teaching practice. Additionally, how AR can be effectively integrated in specific educational levels and subjects (disciplines, fields)? What are the most appropriate teaching methods for specific educational levels, settings, subjects and learning objectives? What mechanisms and methods facilitate teachers to find quality, relevant, accurate, and inclusive AR educational resources? Future research may also explicitly investigate trust, security, safety, privacy, and ethical issues with regard to ARinE. For example, what measures should be taken to prevent bullying, harassment, snooping, and cyber-attacks during ARinE?  
It can also compare various AR-based teaching methods with respect to learners' interest, engagement, motivation, enjoyment and other variables. Other research questions are related to the required AR infrastructure (e.g., AR-related hardware, software, educational resources) for schools, teachers, and learners as well as the cost structure of integrating ARinE (e.g., cost of buying, maintaining, adapting, replacing). How to efficiently design and develop easy-to-use, trusted, secured, safe, inclusive, ethical, and inexpensive AR tools and educational resources? What functionalities should be embedded on AR tools and educational resources? What features should an AR educational resource include in order to decrease learners' cognitive overload, distraction, misorientation, illusion, and confusion? What are the appropriate methods and practices for promoting ARinE and training teachers, learners, and others involved in ARinE? This is an evolving research area that for sure will bring in light many more interesting research findings that we aim to facilitate educators and students' teaching and learning experiences.  
Conceptualization, M.P., A.A.E. and S.A.N.; methodology, M.P., A.A.E. and S.A.N.; validation, M.P., A.A.E. and S.A.N.; formal analysis, M.P. and A.A.E.; investigation, M.P. and A.A.E.; resources, S.A.N.; data curation, S.A.N.; writing--original draft preparation, M.P., A.A.E. and S.A.N.; writing--review and editing, M.P., A.A.E. and S.A.N.; supervision, M.P. and A.A.E.; project administration, M.P. and A.A.E. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
All subjects gave their informed consent for inclusion before they participated in the study. The study was conducted in accordance with the Declaration of Helsinki, and the protocol was approved by the University of Strathclyde Ethics Committee.  
The authors declare no conflict of interest.