# Survey: Using Augmented Reality to Improve Learning Motivation in Cultural Heritage Studies
## 5 System Classification
Another disadvantage in AR is that the tracking methodology based on markers could be intrusive in some scenarios [81]. In the same vein, it is important to consider different aspects that might affect the user's experience; for example, in [91], they mention that in their application, the virtual content takes too much time to appear in the mobile device. An article by [PERSON] [114] mentions that the main factors for the lack of AR pervasiveness are technological/technical limitations (image recognition, internet connection, responsiveness), human interaction (distraction and ergonomic devices) and organizational limitations (handling AR projects, IT infrastructure and financial resources). Challenges for AR include precision, user-tracking, and registering 3D models in a real environment. As [PERSON] [35] notes, these aspects are important to bear in mind when developing an application. In external environments, such as excavations, AR applications could be affected by the light conditions, and therefore, it is fundamental to consider this kind of aspect if the application is to work properly [24]. The success of an AR application also depends on the content available, and it could be affected by aspects such as resolution, illumination, contrast, latency, calibration of the virtual objects with the real world [14], geometric precision, capture of details, photorealism, portability, efficiency, etc. [76]. For example, the articles by [PERSON] and [PERSON] [91; 115] mention that perceived usefulness is a factor that determines the use of AR applications [91], and that the popularity of an exhibition is not dependent on the museum, but rather on the content offered and the device used [115]. [PERSON] [13] notes another point that is important to work on when using AR in CH, namely, choosing places that are important for current and future generations to remember. Furthermore, [44] mentions that other factors to consider in CH AR applications are the characteristics of the urban environment, the constant changes this kind of technology undergoes, which means teachers and students will need (re)training, and keeping the information updated. What Advantages and Disadvantages do AR Technologies Have Compared to Other Technologies Such as VR and MR? AR allows interaction with the real world to take place and is enriched by superimposing virtual information in real-time, thus enhancing human perceptions of CH by reconstructing physical archeological sites and preserving them for future generations [35]. It does not replace the user's reality [11], but it does allow for on-site construction, thus avoiding physical difficulties [35]. Neither does it generate isolation among users [38] but rather generates interaction with other users, thus improving the CH learning experience [35]. Furthermore, AR reduces the time consumed in recreating virtual objects [81] because the user perceives both realities simultaneously [91]. It also avoids problems such as motion sickness [81]. [PERSON] [30] describes an application they refer to as 'edutainment', that uses AR in archaeological parks where students are encouraged to more involved in the learning process through games. As AR only manipulates part of the real environment, it is a viable technology in terms of technological and economic cost, as well as for creating content [15; 41]. Unlike VR, where everything is a virtual object, AR replicates the authenticity of the artifacts and does not require specialized hardware to operate an application [107]. In VR, the user's location is not important, but the problem is that these environments are synthetic and do not offer real artifacts, and so the authenticity of the CH elements are lost [57]. AR also provides real augmented visual perceptions of the information or content because, unlike VR, AR does not change the real world at all [41], thus allowing users the opportunity to experiment with real objects [23].