*5.2. Manipulability*

On perceived manipulability in the survey, QM4 and QM6 items had a median of 6.0 and a mean over 5.4. The others had a median of 5.0 and a mean between 5.08 and 5.44. While QM4 obtained the highest score, QM3 had the lowest median. The device was small, and the users did not have problems related to their arm comfort. Only small difficulties in holding the device while operating the application were reported.

Similar to the comprehensibility construct, very close values were obtained for all the experiments for the manipulability construct: Constanta (mean = 93.16), Rome (mean = 93.65), and Sulmona (mean = 94.53).

## *5.3. Enjoyment*

For perceiving enjoyment, only QE3 had a median of 5.0, while the other three items had a median of 6.0. The mean ranged from 5.13 to 5.68. For this construct we obtained the highest values. QE1 achieved the highest score from all the questions that were proposed in the survey. The users liked to use the application. Good results were also obtained for QE3, which indicated that the objective set at the beginning was met. Only eight participants rated 5 in the Likert-scale for this question, and the others rated it 6 and 7.

The values obtained for this construct were: Constanta (mean = 94.87), Rome (mean = 96.19), and Sulmona (mean = 96.88).

#### *5.4. Usefulness*

On perceived usefulness, all four items had a median of 5.0 and a mean between 4.84 and 5.12. Item QU1 had the lowest average score. Some users suggested that the application might be improved with text to better reflect its purpose and to have more historical information about Ovid. Better scores were obtained for the items related to audio content, i.e., when Ovid's poem was heard in the background.

Perceived usefulness achieved the lowest score in the three cases: Constanta (mean = 88.55), Rome (mean = 86.43), and Sulmona (mean = 85.16).

Usefulness was the area of the survey where the users had the most variable results. The standard deviation ranged from 0.81 to 0.90. However, the highest value for standard deviation was obtained for item QM3 (SD = 0.94).

Briefly, we can conclude that participants enjoyed using the application and were mostly satisfied with its content. Although some historical data were missing, the application was easy to use, it was useful, and it confirmed the fact that the development of new interfaces for promoting CH is a sustainable action well-received by the public. Relevant photos and screenshots from the experiments are presented in Figure 9.

In Figure 9a2 the modelled house of Ovid is presented, placed on the top of the ruins of the real ancient house from Constanta. Figure 9c represents another modelled house, and the child version of Ovid walking.

The technology allowed registration of the model in different places accessible to tourists. It took into account their orientation, and adapted to their viewpoint. A wide variety of tourists can use the device (Figure 9a1,a3,b).

**E F** 

**Figure 9.** Mobile Augmented Reality (MAR) application used in (**a**) Constanta, (**b**) Rome, and (**c**) Sulmona.

#### **6. Conclusions**

Despite the fact that MAR applications show great potential in the CH area, the number of works that provide an analysis of user acceptance is relatively low. This work aimed to add value in this respect, and proposed a user study to assess participants' perception regarding the use of an MAR application with historical information related to CH. A prototype AR application was implemented as a subject for the study, and a questionnaire was used for collecting the data. Three sessions were conducted in three different locations, with participants from several countries. The questionnaire items, other than demographic information, intended to analyze the following four constructs: comprehensibility, manipulability, enjoyment, and usefulness.

The results show that the usability of the MAR application and the interaction was considered appropriate. Good results were obtained for all four constructs that were analyzed.

It should be noted that MAR technology has proved to increase the accessibility of tourists to intangible heritage. Tango technology allows users to create and save maps of the environment that are linked to the starting point of a scene, thus making it easy for developers to create AR applications.

The application meets the proposed objectives. Most of the users agreed that OvidAR had attractive content and met the usability requirements, providing a positive experience during the interaction. AR is a technology that will be more accessible in the upcoming years, and people will be more receptive in using it. In the field of CH, institutions and companies started to use this technology in order to provide more realistic experiences for tourists and museum visitors. In this regard, we think that AR technology represents a proper media for the sustainability of CH conservation and/or documentation.

Nevertheless, this study is not exhaustive. Our aim was not to obtain data that was statistically reliable, but to present a method that can be used sustainably to disseminate CH events at an international level. Future developments can include: improving tracking stability by fine tuning the Tango-related parameters, improving the 3D models to make them more realistic, or conducting further usability evaluations that involve more constructs and participants. That being said, we conclude that MAR could be one of the answers to various problems faced by the CH area in the 21st century, such as the lack of funding, the poor impact on cultural growth, and the weak cultural cohesion of neighboring countries.

**Author Contributions:** Conceptualization, R.G.B., C.-C.P. and D.-M.P.; methodology, G.D.V. and C.-C.P.; software, R.G.B. and G.D.V.; validation, D.-M.P., and M.C.; data curation, G.D.V.; writing—original draft preparation, R.G.B.; visualization, M.C.; supervision, M.D. and M.C.; project administration, M.D.

**Funding:** This paper is supported by European Union's Horizon 2020 research and innovation program under grant agreement No 692103, project eHERITAGE (Expanding the Research and Innovation Capacity in Cultural Heritage Virtual Reality Applications).

**Acknowledgments:** We also acknowledge the participants of the 6th Edition of the Summer School on Virtual Environments organized at Ovidius University of Constanta, Romania.

**Conflicts of Interest:** The authors declare no conflict of interest.
