# Interaction in eXtended Reality Applications for Cultural Heritage
## 5 User Experience Evaluation  
Usability evaluation goals encompass both the exploration of novel interaction approaches and success in the exploitation of the technology in use. A common benefit of these different usability evaluation goals is the provision of informative feedback to designers and developers concerning users' attitude towards the adoption of the XR technologies. The development of our XR applications is accompanied by relevant usability studies on genuine and overall user experience with interactive digital storytelling. An additional objective is to focus on measuring success in achieving specific features such as edutainment and immersion. In our previous UX studies, we employed the qualitative approach for the initial evaluations of the Mostar Cliff Diving VR [48] and the Sarajevo War Tunnel [47], and the quantitative evaluations for the Kyrenia [51] and Baiae [22] interactive digital stories, and for the follow-up studies on the Mostar Cliff Diving VR [49]. The quantitative studies enable our team to assess the level of development of the application and compare different solutions. This is the reason why we design our quantitative studies  
Figure 6: Different types of informative content on the Sarajevo Roman Heritage Augmented Reality Application. according to the specific benchmarking framework [52], which is to enable comparison between the studies and to identify patterns in user preferences. The most recent example of a quantitative usability evaluation study is that of the \"Crvene stijena\" VR application developed for the Niksic Museum. We will present the overview of the evaluation results for this study as an example of our studies. The framework for the usability studies we developed is built upon the constructs adopted from the UTAUT model [53]: Performance Expectancy (PE) and Effort Expectancy (EE). The UX questionnaire measures the following sub-scales: immersion and edutainment, both linked to the Performance Expectancy (PE); and perceived ease of use, linked to the Effort Expectancy (EE). The questionnaire was organized into three sections:  
1. Introductory part with demographic data;
2. Quantitative UX evaluation comprising three sub-scales addressing immersion, edutainment, and ease of use;
3. Open questions part where users can express their opinion and indicate the most favorable and the most problematic parts. The evaluation of the sub-scales was performed using a 5-point Likert scale. In our previous studies, participants were recruited by invitation and demographic data were used to reflect a balanced composition regarding the age, gender, education, professional background, etc. The novelty of this study was that the participants were visitors during the opening exhibition at the Niksic Museum, and the demographic data reflect their composition: balanced regarding the age, with half of the participants being secondary school students. The questionnaire structure and overview of measured statistics as well as the mean and the standard deviation are presented in Table 1. Mean values for Performance Expectancy, more specific for the items measuring the immersion, are in the range of 4.31-5.00, while the edutainment items are in the range of 4.44-4.88. Mean values for the Effort Expectancy items reflecting ease of use are in the range of 2.88-4.81. The evaluation results are in line with our previous conclusions, that the quality of the narrative has a positive effect on immersion and edutainment, even in the presence of challenges regarding the ease of use. Mean values for the overall rating of the sub-scales are: 4.76 for the immersion, 4.68 for the edutainment, as compared to 3.94 for the ease of use. We are aware that many users at the sites of the museums had an opportunity to try completely new technology such as VR, and this produced more positive results compared to very experienced VR users.