Based on the review of research and scientific works on the broadly understood application of AR in education, one cannot help but notice that the level of interest in utilizing the technology is rapidly increasing. However, the AR publication’s growth dynamics slowed down in 2020, probably due to COVID-19 pandemic. On the one hand, this is because of a significant decline in post-conference publications caused by mass cancellations of such events. On the other hand, it should be noted that any research work on AR often requires contact with a large number of users of the implemented systems, which given the restrictive sanitation regulations has been significantly hindered. Despite a number of such negative factors, an increase in publications on the subject was recorded. Interestingly, significant growth in the share of Open Access publications has been noticeable for approximately three years. It is a consequence of changes introduced in the business models of publishing houses and scientific research institutions. Worldwide publications on AR applications are geographically dominated by researchers in Asia, Europe and North America, reflecting the technological leadership of these continents. While a large portion of them comprises very worthwhile scientific publications, a very disturbing phenomenon was observed. Among the reviewed papers, there was an unnatural overrepresentation of publications originating from Indonesia, which unfortunately differed significantly at the substantive level from the rest of discussed works. Probably the verification system was at fault here. Mobile devices are still the most widely used technology solution for AR systems. Compact size, built-in rear video camera, autonomous use, high system standardization, and relatively low purchase cost are the attributes favouring this solution. However, users of mobile AR systems notice some disadvantages, the most important being the low level of immersion and the discomfort of use. Mobile devices virtually always require hand-holding and the use of static grips severely limits the application’s functionality. The exceptions are projector-based AR systems created for users such as vehicle drivers, whose position and field of view are rather fixed. AR systems created as glasses with built-in transparent displays do not have these disadvantages. Based on the review, there is an observable increase in interest in products such as HoloLens. The upwards trend stems from a gradual decrease in the cost of such devices and a more competitive choice of products (e.g. Apple). What’s more, they are definitely the most comfortable form of experiencing AR. Solutions based on static workstations equipped with a camera, computer and monitor or projector are already present in trace quantities, absorbing the interest of researchers from developing countries as the cheapest alternative to commercial solutions. AR systems are also more often being used as a part of MR solutions. Visual markers, now past their prime, are being displaced by multi-camera object recognition systems. Real surroundings enriched with interactive 2d/3d visual forms provide numerous educational, cognitive and assistance opportunities. They allow the user to fully concentrate on the task at hand, and the AR system acts as a teacher, assistant or consultant. The review shows that the main form of interaction undertaken with an AR system is the image. Through the use of multiple sensors, active interaction performed using gaze has become possible. AR systems are beginning to use gaze as a complement to controllers and the indicators they control, thus interactions become more comfortable and intuitive for the user. Additionally, the sound is still an important form of communication and this includes both audio and voice/speech messages. AR systems equipped with sets of controllers often use haptic communication, which works especially well in situations of visual focus on other elements of the scene. However, there is a noticeable trend of the complete elimination of controllers favouring the user’s hands. The user can be wearing gloves with tracing or haptic systems, or bare hands can be used and their detection is performed by optical tracking. In the reviewed works, other external devices for multisensory interaction with the system are occasionally found. But these should be considered as niche and often highly specialized solutions. However, considering the constant development of technology, such as motion capture, speech, gaze and brain activity recognition, the feature of AR systems will be based on multi-channel human-computer interaction. Special attention should be directed to haptic interfaces and muscle-electrical stimulation solutions, which can significantly improve human-computer feedback. AR technology is increasingly utilized in general education and life sciences, especially in physics and chemistry. It can be explained by the fact that some concepts and phenomena are easier to understand if they are visualized. Additionally, AR allows the presentation of information in an attractive and engaging manner. Education supported by AR and VR becomes much more tailored to the way students who are tech natives experience the world [
187]. Gamification elements and audiovisual content may significantly increase students’ involvement and it is proven that learners improve their performance using AR. What is more, AR has been implemented with great success in engineering, mainly for machine process simulations and architectural visualisations as future engineers need to develop three-dimensional skills as well as spatial imagination. AR supports them in gaining these essential engineering abilities by illustrating and explaining complex spatial constructions, mechanical or electrical mechanisms and highly abstract concepts such as electromagnetic fields etc., and drawing users’ attention to crucial elements. Learners are able to practice critical decision-making and safely explore hazardous and emergency situations. Another field of education that benefits from AR are medicine. The greatest advantage of AR medical training is the possibility to interact with simulated body parts and gain experience that is closer to reality than textbook knowledge or video footage. It is noteworthy that medical training appears to be more dominated by VR-based applications compared to applied medicine which is more AR-focused. Surprisingly, there is relatively little interest in solutions aimed at broadly understood support of people with disabilities, resulting from the low awareness of universal design in research and scientific communities. The presented review outlined that establishing a standard or generally used framework for evaluating AR solutions, although being developed for over a decade, has not reached as much consensus as evaluating mobile apps or websites. Most authors use standard usability testing methods based on HCI guidelines, tailoring tools and techniques to the type of project. It is always a challenge of choosing the tools that fully suit the purpose of the evaluation. Tools available for use include questionnaires, interviews, observation grids, and monitoring technology support and they are built according to the chosen research methodology, or the combination of more than one, and maybe combined in different techniques such as focus groups, walk-throughs, real case scenario simulations, and think aloud testing. The type of data and the method for its collection must be congruent with the purpose of the evaluation and the factors chosen to be evaluated. A systematic literature review by Valeria Martins [
176], compiled several commonly used features for measuring the usability of AR applications such as ease of use and learning, user satisfaction, and application attractiveness. However, the evaluation may include additional concerns less orientated towards user experience and more linked to its efficacy in enhancing the learning process. Both the UX and the application aim-related issues must be given similar priority. It is recommended to use an iterative approach during the development process to ensure a decrease in the number of problems that will appear during the evaluation stage. However, based on the literature review, we have noticed a worryingly low validation level. It seems that scientists often focus their attention on achieving an intended goal without verifying effectiveness. However, unvalidated solutions should not be quickly introduced, especially in medical and engineering education, as they can stimulate acquiring bad habits or wrong actions. As a result of the combination of an iterative approach during the development stage [
188] and a rigorous attitude towards the evaluation phase, it is possible to collect objective data (i.e., task completion times and accuracy/error rates, scores, position, movement, number of actions, etc.) and subjective data (i.e., subjective user ratings and opinions) linked with user preferences, interaction problems, system errors and even missing functionalities. Unfortunately, we have noticed that validation methods providing objective data (e.g., based on biomedical measurements) are used relatively rarely. Their substantive value is much more reliable than users’ subjective opinions or feelings. Thus, objective validation methods should be considered to measure user involvement, creativity, focus, and emotional state. This type of validation allows the developers to know exactly where and under what circumstances the user encountered difficulties. It is an incomparably better approach than a questionnaire/interview in which the user provides a subjective general assessment. Continuous development of external devices, such as wireless EEG headsets [
189], eye/hand-tracking optical sensors and motion capture or various bio-marker monitoring devices [
190], should encourage researchers to utilize objective validation methods to prevent the creation of a useless or potentially counterproductive application. In summary, we should expect continued vigorous growth of interest in the implementation of AR systems in education, especially in teaching and learning at High Education Institutions, more so because many of them can be successfully used to develop skills of students that will perform their jobs and support remote communication, control, and management systems.