# Engineering the Future: Evaluation of Virtual Reality Across Project Lifecycle Stages
## 4 Results
### Perceived Practicality of VR Across Project Stages  
A GLM Repeated Measures procedure was conducted to examine perceived practicality of VR across various stages of the project lifecycle. The assessed stages included Proposal and Investor Recruitment, Specification and Requirement Definition, Concept Formation, Design and Surveys, Development, Testing, Training, and Maintenance. Perceptions were measured on an ordinal scale from 1 (very little) to 5 (very much), based on participants' responses to the question: \"To what extent do you think the use of VR would be beneficial at each stage of the project?\" The analysis aimed to assess how perceptions of VR's usefulness varied across the different lifecycle stages. The dataset contained 56 valid responses, all with complete data for the relevant variables. No missing data was observed, ensuring the robustness of the analysis. The GLM method was used to test the differences in perceived practicality of VR across these project stages. The descriptive statistics for each project stage are summarized in Table 1, which lists the means and standard deviations for each stage. As shown, the Training stage had the highest perceived practicality (M = 4.00, SD = 1.04), followed by Proposal and Investor Recruitment (M = 3.64, SD = 1.10). In contrast, the lowest perceived utility was reported for the Specification and Requirement Definition stage (M = 2.89, SD = 1.11), suggesting that VR was seen as less practical at this early stage of the project lifecycle. The Multivariate Test results showed a highly significant multivariate effect (Pillai's Trace = 0.49, F = 6.78, \(p\) < 0.001), suggesting that the perceived practicality of VR differs significantly across the stages of the project lifecycle. This was confirmed by the significant results from Wilks' Lambda, Hotelling's Trace, and Roy's Largest Root (\(p\) < 0.001 for all). These findings indicate that the stage of the project plays a key role in shaping perceptions of VR's usefulness. [PERSON]'s Test of Sphericity results indicated a significant departure from sphericity (W = 0.31, \(\chi^{2}\)(27) = 59.98, \(p\) < 0.001). This test assesses whether the assumption of equal variances of the differences between all pairs of levels is met. The significance of the result indicates that the assumption of sphericity was violated. Therefore, the Greenhouse-Geisser correction was applied to adjust the degrees of freedom for the F-tests, as indicated by an epsilon value of 0.76. This adjustment ensures the robustness of the statistical results and accounts for the lack of sphericity. The Greenhouse-Geisser (0.76) and Huynh-Feldt (0.85) epsilon values indicate the degree of correction needed due to the violation of sphericity. The results suggest that while the sphericity assumption is not fully met, the Greenhouse-Geisser correction provides an adequate adjustment for this violation. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Project Stage** & **Mean** & **SD** \\ \hline Training & 4.00 & 1.04 \\ \hline Proposal and Investor Recruitment & 3.64 & 1.10 \\ \hline Concept Formation & 3.25 & 0.99 \\ \hline Development & 3.20 & 1.12 \\ \hline Testing & 3.18 & 1.19 \\ \hline Maintenance & 3.36 & 1.15 \\ \hline Design and Surveys & 3.05 & 1.07 \\ \hline Specification and Requirement Definition & 2.89 & 1.11 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Perceived practicality of VR across project stages (ordered by mean). The Tests of Within-Subjects Contrasts for the perceived practicality of VR across project stages reveal significant findings. Notably, the cubic contrast (F = 13.47, \(p\) < 0.001) demonstrates a significant effect, suggesting that **the relationship between project stages and the perceived practicality of VR is not linear but rather follows a more complex pattern**. Additionally, the fifth-order contrast (F = 25.75, \(p\) < 0.001) shows a very strong effect with high observed power (0.99), highlighting significant variability in the perceived usefulness of VR across different stages.