## 4 Experiments and Evaluation
### Experiment in University
#### 4.1.2 Discussion and Results  
Figure 11 is the result of the survey about the usefulness of the R-WOSARLS during the task stage experiment. For the questionnaire item Q1, the mean value is 4.08, showing that the learners agreed that the latitude and longitude lines in AR view are useful for observing and understanding the azimuth and elevation angle of the constellation in the sky. During task 2, participants were asked to guess the azimuth and elevation angle of the targeted constellation, where only one answer was right, but most of the participants said that they did not know about the azimuth and elevation angle of the constellation, as they found it was challenging to view the constellation compared to the Sun and Moon during daytime. During task 2, searching for the targeted constellation in the AR view was time-consuming and made participants locate the targeted constellation with body scale (hand) image guidance. Almost all of the participants agreed that the body scale method was useful and more convenient to search for the targeted constellation. They would like to practice searching for the targeted constellation in the sky with their hands without the system. All of the participants in the experiment said that they had an intuitive feeling regarding the elevation angle of hands through using the system, which is something they can easily use to locate stars or constellations in the real starry sky. This is clear from the mean of 4.33 for Q2. Participants confirmed that the \"OneDay\" function in the AR view interface was very helpful in observing the targeted constellations one-day orbit in the sky (Q3). The mean of Q4 was 4.58, proving that the participants greatly agreed that the \"DisplaySeasonConstellationStarry\" function in the AR view interface is useful in observing and studying the seasonal constellation across different seasons. The Q1, Q2, Q3, and Q4 questionnaire items about the usefulness of the AR view interface had a mean above 4.00, which indicated that the AR view is very useful for learners to observe and study the seasonal constellations, and provided a visual real-world learning experience, as it is not often convenient for people to look for constellations in the starry sky due to light pollution, geography or other factors. However, the mean of Q5 regarding universe view interface was only 3.50, which is much lower than the value of questions items regarding aforementioned AR view function since most participants considered that it was better to use a more intuitive interface and have more content to assist users in understanding the mechanisms of seasonal constellations. Figure 11: The result of usefulness questionnaire of R-WOSARLS. Regarding the interface design of R-WOSARLS, most of the learners considered that the R-WOSARLS was easy to operate, and the mean value of Q6 is 3.75, as shown in Figure 12. In addition, the result of Q8 (4.25) showed that the learners agreed that the response time when operating the system was brief, which helps the users operate the system and complete their observational task. However, participants reported that sometimes the interface was not clear or easy for the learners to understand when they were doing tasks, with a mean value of only 3.42 for Q7. Based on the report of the interview from the participants, it is suggested that some parts of a system interface should be improved, such as the size of the text should be larger and that a different set of text colors could make the interface easier to use. It was found that this system helped users enhance their motivation regarding seasonal constellations (Q10), as shown in Figure 12. Eight participants had limited knowledge about constellations. After they used the system to complete observational tasks, participants' knowledge on seasonal constellations was improved, and they thought the system was very interesting, with a mean value of 4.25 for Q9.