## 3 Methodology
### Experiment  
For the sake of convenience, we chose the fourth floor of the nearby National Taiwan University of Arts Library as the experiment venue. It is 16.5 m \(\times\) 13.24 m. We adopted a between subject design with one participant at a time to avoid any unnecessary collisions. During the experiment, the participant was given an iPhone XR manufactured by Apple. The experiment was divided into two scenarios. A text scenario and an AR scenario. In the text scenario, the smartphone screen only displayed the title, author, and call number of a book, and the participant was required to located the book based on the displayed text. In the AR scenario, the location of the book in the physical space was directly displayed along with the title, author, and call number of the book. The details are as shown in Table 1 below.  
We chose six random books in the library and referred to them as Books A, B, C, D, E, and F. Figure 5 displays their locations in the library. The experiment required a physical venue; to recruit participants nearby who were familiar with operating the smartphone, we adopted purposive sampling, focusing on students and faculty members at National Taiwan University of Arts over the age of 18. We recruited a total of 60 participants, who were randomly assigned to Group I or Group II. These two groups only differed in the order in which the books were searched for. The experiment was  
Figure 4: (a) 2D Visualizations of the Viewers Paths; (b) View Path on Smartphone Screen.  
divided into two stages for each participant. In Group I, the participants first searched for Books A, B, and C using the text scenario. After completing this stage, they then searched for Books D, E, and F using the AR scenario. In Group II, the participants first searched for Books D, E, and F using the text scenario. After completing this stage, they then searched for Books A, B, and C using the AR scenario. We compared the behaviors of the Group I participants who searched for Books A, B, and C using the text scenario and those of the Group II participants who searched for Books A, B, and C using the AR scenario. Then, we compared the behaviors of the Group II participants who searched for Books D, E, and F using the text scenario and those of the Group I participants who searched for Books D, E, and F using the AR scenario. Finally, we analyzed the differences between the book-finding behaviors in the text and AR scenarios. Figure 6 presents the procedures of the experiment.  
In the experiment, the participants first scanned a start image (Figure 7a) as instructed and then searched for the book based on the information provided on the smartphone screen (Figure 7b). Once they scanned the cover of the right book to indicate that they had successfully found it (Figure 7c), the screen would then show the information of the next book. Whether the participant was in the text scenario or in the AR scenario, the smartphone would record the trajectory, time, distance travelled, and direction as they moved through the physical space. At the end of the experiment, it automatically uploaded the data to a cloud for further analysis and comparison of the participants in the two scenarios. After the end of the experiment, the participants were given a questionnaire regarding the usability of the AR guidance system and any suggestions they might have for future improvements.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Scenario** & **Text Scenario** & **AR Scenario** \\ \hline \multirow{2}{*}{**Explanation**} & Only name and call number of & Location of book marked using \\  & book are displayed in text form & AR in addition to name and call \\  & & number of book \\ \hline \hline \end{tabular}
\end{table}
Table 1: Two experiment scenarios.  
Figure 5: Location of six books in experiment venue.  
Figure 6: Experiment procedures.