A correlation matrix is a useful tool to visualize pairwise correlations between all variables in a dataset. Its elements represent the correlation coefficient between two variables, ranging from -1 (perfect negative correlation) to 1 (perfect positive correlation), with 0 indicating no significant correlation. The partial correlation matrix, on the other hand, measures the unique association between two variables while holding constant the effects of other variables. By removing the shared variance due to other variables, partial correlations reveal the direct relationship between the variables of interest. Figure depicts the correlation and partial correlation matrices, showing how varying the input parameters (fiber diameter, fiber concentration, binder concentration, GDL thickness and compression ratio) affect the GDL performance. For additional insight, three properties were also added with respect to the database used in the training set: Porosity, Geometric Tortuosity, and Resistivity. The correlation matrix reveals an association between porosity and both fiber concentration and compression ratio. However, the partial correlation matrix suggests that compression primarily drives this relationship. This implies that increasing compression leads to a decrease in porosity. Focusing more on the partial correlation matrix, tortuosity exhibits a positive/negative correlation with fiber diameter, binder concentration, GDL thickness, and compression ratio. Conversely, inplane thermal and electrical conductivities are positively/negatively correlated mainly with fiber diameter, indicating enhanced conduction through the fibers with increasing diameter. Throughplane conductivities, however, demonstrate a comparable dependence on fiber diameter, fiber concentration, and thickness. Binder concentration appears to primarily impact TP diffusivity, potentially due to its distribution within the GDL microstructure. Contact resistance displays the weakest correlation with GDL thickness, as expected since the thickness does not necessarily affect the contact points between the carbon fibers and the MPL layer.