## 3 Results
### Summary of the Selected Articles
#### 3.1.1 Education  
According to the studies found, education is probably one of the most explored fields where AR has been applied, with 98,812 articles found in the five databases chosen; it was the discipline with the most scientific production in the period chosen. It was interesting to find that training or education is implicit in all disciplines since AR is a technology that needs to be learned before its application. Additionally, there were certain coincidences in the benefits of AR application in education that were mostly an important increment in learning motivation. Figure 5: AR research trends according to databases and disciplines. Figure 6: AR articles encountered by discipline. From the 12 articles studied, there was an AR education (AREd) app where students from different educational levels received 3D materials to be applied in school practices; this was evaluated to determine the knowledge obtained, and it was found that AREd incremented the learning speed and understanding. However, one of the difficulties encountered was that the adaptation to AREd was complicated for some of the students [21]. Different from the last example, in another study, although the use of AR was complicated at first, the students adapted to it easily and soon showed acceptance. AREd was implemented to interact in inquiry-based learning in a teacher-student system. For this research, four videos were implemented in two high schools, with two of the videos being adapted to AR, leaving the other two without this feature. AREd again showed a positive impact; however, teachers still had to develop timely questions and suggestions to increase the battery of data. This clearly supported the inquiry-based learning performance. The model was built with 3D Max, and the AR application program was developed with Unity3D and Vuforia [22]. Understanding was also part of a study of AREd, applied and compared to a common booklet written to improve knowledge about cerebrovascular accidents. In this research, 101 participants were randomized and placed into two groups to complete a lesson using a printed handout (n = 50) or an AR digital mode (n = 51). The educational interventions were identical and described important aspects of the physiology and pathophysiology of a stroke, as well as the anatomy of the brain. Applicants answered a pretest multiple-choice questionnaire to assess prior understanding before the lesson, followed by an additional multiple-choice test and a Likert-scale survey after completion. In the end, participants had better interaction and stimulation with AR, although the results given showed that the two forms of learning obtained almost the same accomplishments [23]. AREd is at an early stage for students of applied health sciences at the University of Ciudad del Cabo, where this research was applied to impact the motivation of student learning. Intrinsic motivation theory was used to explain motivation in the context of learning. The attention, relevance, trust, and satisfaction (ARCS) model guided understanding. A total of 78 participants were examined who used the augmented reality mobile app and completed the pre- and post-use questionnaires. The results showed that the use of an AR mobile application increased the students' learning motivation. The motivating factors of attention, satisfaction, and trust increased, and these results were found to be significant. Although the relevance factor showed a decrease, this turned out to be trivial [24]. Geo + was an AR application presented to support the learning of solid geometry in 96 third-grade students, looking for the effectiveness of learning and the workload in the acquisition of knowledge. The results were satisfactory in gaining learning with great appreciation by students for its simplicity of use. The tools used were Unity, UnityLibrary, Unity Engine, GameObject, and Vuforia [25]. Additionally, in medicine, a biological microscope based on virtual reality (VR) and AR technology was made for a learning system.