# Developing a BIM-Based MUVR Treadmill System for Architectural Design Review and Collaboration
## 5 Validations
### Results  
Eight participants agreed to join the testing, and they were divided into two groups. Group 1 consists of four practitioners, while Group 2 includes four students. The practitioners are experienced architects practicing in Hong Kong. They have been involved in various types and sizes of building projects, and their principal job duties are to plan, develop, and implement the architectural design. The students are final-year students studying the undergraduate program of architecture in Hong Kong. They have received basic training in computational design in architecture. All participants have the basic knowledge and know-how of using VR devices but no experience with VR treadmills or similar locomotion platforms. Figure 6 shows a pair of participants testing the system inside the BIM laboratory. After the testing, all participants were asked to rate their experiences in using the system based on the evaluation measures with a 7-point Likert scale, whereas 7 represents strongly agree, and 1 represents strongly disagree. The evaluation measures were classified into three groups based on multiple scenarios and design review tasks: (1) user interaction, (2) user locomotion, and (3) system synchronization. Mean scores with standard deviations of the evaluation measures were determined. The normality test was also used to determine if the dataset was well modeled by a normal distribution. Then the two-sample \(t\)-test was conducted to examine whether the opinions of practitioners and students were sufficiently consistent. The mean scores are recognized as having no statistically significant difference  
Figure 5: Multiple scenarios for system testing by a pair of participants: (**a**) conflict resolution, (**b**) design detailing, (**c**) design overview, (**d**) design creativity, (**e**) walking along the corridor, and (**f**) walking along the staircase. when the significance level (\(p\)-value) is higher than 0.05 [44]. Additionally, all participants were requested to rate the overall immersion level, using the system, according to their experiences of accomplishing the hypothetical tasks and the final stage of free walking. Table 1 summarizes the mean scores and results of the \(t\)-test. First, the normality test showed that the sampling distribution of the means is normal. Thus, the two-sample \(t\)-test is valid because the two groups are independent random samples from normal distributions. Second, the means of all participants regarding the interaction experiences are 5 or above, while the measure of design overview received the highest mean (mean = 5.75). This measure also received the highest mean in Group 1--practitioners (mean = 5.5) and Group 2--students (mean = 6). The \(t\)-test found no statistically significant differences between the two groups of participants in evaluating user interactions. Third, the safety of user locomotion on treadmills was evaluated. This measure had the best performance among all participants (mean = 5.63); the mean of Group 1 is 5.25, whereas Group 2 is 6. The results of the \(t\)-test further show that there  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Evaluation Measures**} & **All** & **Group 1** & **Group 2** & \multirow{2}{*}{\(t\)} & \multirow{2}{*}{\( \begin{array}{c}\text{\bf Sig.}\\ \text{\bf(\textit{p}\text{-Value})}\end{array} \)} \\  & **\(n\) = 8** & **\(n\) = 4** & **\(n\) = 4** & & \\  & **Mean (SD)** & **Mean (SD)** & **Mean (SD)** & & \\ \hline \multirow{4}{*}{\ \begin{tabular}{c} Conflict resolution \\ Design detailing \\ Design overview \\ Design creativity \\ \end{tabular}  } &
\begin{tabular}{c} \text{User interaction} \\ 5.13 (1.45) \\ Design detailing \\ 5.00 (1.73) \\ 5.75 (1.20) \\ 5.00 (1.66) \\ 5.00 (1.  
were no significant differences between the two groups of participants in this measure. However, the measures of preciseness and agility similarly received means below 4 in Group 1 only. In particular, the mean of agility is distinctly low (mean = 3.25).