## 4 The Results of Hypothesis Testing
### The Estimation Results of Model
Therefore, Hypothesis H4 (a) is confirmed. However, the effect of Neuroticism Factors (NEFs) on confidence in a decision (CID) was non-significant, with a path coefficient of \((-0.199;\ p>0.05)\). Thus, Hypothesis H4 (b) is not confirmed. The effect of Openness Aspects (OPAs) on the quality of a decision (QOD) was significant, with a path coefficient of \((0.277;\ p<0.05)\). Hypothesis H5 (a) is thus confirmed. The effect of Openness Aspects (OPAs) on confidence in a decision (CID) was non-significant, with a path coefficient of \((0.232;\ p>0.05)\). Therefore, Hypothesis H5 (b) is not confirmed. The effect of Self-Assessed Knowledge (SAK) on the quality of a decision (QOD) was found to be non-significant, with a path coefficient of \((-0.030;\ p>0.05)\). Thus, Hypothesis H6 (a) is not confirmed. The effect of Test-Assessed Knowledge (TAK) on the quality of a decision (QOD) was found to be significant, with a path coefficient of \((0.266;\ p<0.05)\). Therefore, Hypothesis H6 (b) is confirmed. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Criterion** & **Indicators** & \(\mathbf{R^{2}}\) & **Path Coefficient** & \(\mathbf{\hat{f}}\) \\ \hline Quality & EXC & \(0.628\) & \(-0.213\) & \(0.090\) \\  & AGF & & \(-0.210\) & \(0.109\) \\  & COA & & \(0.260\) & \(0.118\) \\  & NEF & & \(-0.185\) & \(0.075\) \\  & OPA & & \(0.277\) & \(0.168\) \\  & SAK & & \(-0.030\)\({}^{\text{(ns)}}\) & \(0.002\) \\  & TAK & & \(0.266\) & \(0.122\) \\ Confidence & EXC & \(0.333\) & \(0.010\)\({}^{\text{(ns)}}\) & \(0.000\) \\  & AGF & & \(-0.211\) & \(0.061\) \\  & COA & & \(-0.002\)\({}^{\text{(ns)}}\) & \(0.000\) \\  & NEF & & \(-0.199\) & \(0.048\) \\  & OPA & & \(0.232\) & \(0.066\) \\  & SAK & & \(0.026\)\({}^{\text{(ns)}}\) & \(0.001\) \\  & TAK & & \(0.322\) & \(0.100\) \\ \hline \hline \end{tabular} Note: non-significant (\({}^{\text{ns}}\)) at the ¡0.005 level (one-tailed test).  
\end{table} 
Table 5: Effect sizes and structural model results. The effect of Self-Assessed Knowledge (SAK) on confidence in a decision (CID) was found to be non-significant, with a path coefficient of (0.026; \(p>0.05\)). Consequently, Hypothesis H7 (a) is not confirmed. The effect of Test-Assessed Knowledge (TAK) on confidence in a decision (CID) was found to be significant, with a path coefficient of (0.322; \(p<0.05\)). Hence, Hypothesis H7 (b) is confirmed. The innovations of this study lie in its comprehensive approach to analyzing decision-making quality and confidence within engineering design. A key novelty is the integration of the Big Five personality traits with both self-assessed and test-assessed domain knowledge, providing a holistic understanding of how these factors interact to influence decision outcomes. This approach goes beyond prior research that typically examines personality or knowledge in isolation. The study also introduces a multi-faceted evaluation methodology that combines subjective assessments, expert validation, and machine learning techniques (Naive Bayes model), ensuring robust and unbiased decision quality assessments. Additionally, the use of simulation games to replicate real-world decision-making scenarios adds ecological validity to the findings, making them highly applicable to professional engineering challenges. Unlike previous studies that often rely on homogenous participant groups, this research includes diverse participants from various academic and cultural backgrounds, enhancing the generalizability of its findings. Furthermore, the differentiation between test-assessed and self-assessed knowledge offers new insights, revealing that decision confidence is more strongly influenced by validated knowledge than by perceived competence. This distinction underscores the importance of factual knowledge validation in training and professional development. Overall, the study's practical implications are significant, emphasizing the alignment of tasks with individual personality traits and the prioritization of objective knowledge in decision-making roles.