# Survey: Using Augmented Reality to Improve Learning Motivation in Cultural Heritage Studies
## 5 System Classification
For example, [PERSON] and [PERSON] [107] mention that VR creates complete immersive environments but lacks the stimulation of senses like the smell because the environment is not real. AR has the potential to transform the ways we learn about our world and the places and elements around us. [PERSON] [33] mentions that, in the case of prehistoric caves where their access is restricted, AR allows the user to visit the real places virtually. For museums, the use of AR provides thoughtful and intuitive interaction with the objects on display to the public [32]. The disadvantage that AR has compared to VR is that the objects from the real and virtual worlds must coexist and be aligned; thus AR needs to have greater precision [11] than VR. As well, [116] mentions that there is evidence that many of the AR devices and some of the content in AR can generate confusion, dissatisfaction, physical fatigue, etc. External aspects such as illumination, reflections, shadows, and weather are also noted as being able to affect the workings of the applications. For example, [87] describes an application used in the exterior and interior of a temple. When there is too much light or too many shadows on the engravings, the functionality is affected at the moment the user wants to watch the augmented content. [PERSON] [15] mentions that [PERSON] [117] identifies a number of the advantages VR has over AR: (i) in its virtual world, VR allows changes to be made to the relative size of the objects, (ii) the user can interact with, and design all of the virtual world themselves, (iii) objects that are difficult to represent in the real world can be created and visualized and (iv) user experiences are more secure and safer than in places where interaction with real objects could affect other users [5]. For example, article [70] shows that VR helps engineers to visualize different techniques in a 3D environment for military training that feigns emergency situations but avoids possible damage or accidents because it all takes place in a virtual world. However, that said, if in VR the virtual world is more interactive in content, the users might want to manipulate or sabotage it [118]. MR, on the other hand, provides the user with the advantages of both the AR and VR technologies [14,119], but its drawback is that it currently uses expensive devices (for example, Hololens from Microsoft) to show content [51]. **What Tools or Frameworks for Developing Applications in AR are Used in the Creation of CH Contents? **  
To determine which tools or frameworks for developing applications in AR can be used, a comparative table was drawn up (Table 2) depicting the characteristics that each has. The systems analyzed in Table 2 were evaluated to identify which would be the most suitable for resolving the challenges mentioned before, on technological and economic levels, and by taking into account the analysis presented in Table 1.  
Table 1 reveals that most of the systems use handheld devices, and most of the AR content is executed in internal and external environments with tracking methodologies such as QR codes, 2D images/3D models, GPS, and sensors. Nevertheless, in the case of QR codes and 2D images/3D models, these systems are focused on internal environments while GPS and sensors are used in external environments. Table 2 contains information about the version, the tracking methodologies that can be implemented, where a + symbol indicates the characteristics that can be used or--if it does not have that characteristic, the platforms that support AR (Unity, Android, and IOS) if it is open source, if it needs a license to use it, if it is available commercially and how much each license costs. **Does the Use of AR Improve Student Learning Motivation in Topics Related to CH? **  
From the analysis, it is deduced that AR improves the learning experience [23,82] and extends it interactively [24] because it can be used as an auto guide for CH resources.