In agreement with the analysis of the QDO model, recent studies relying on large datasets (7 k structures from the GDB-13 dataset as well as the tmQM dataset of 86 k transitional metal complexes) suggest that there's no overall correlation between HOMO-LUMO gap and polarizability . Nevertheless, correlation has been observed both experimentally and computationally for different classes of structures (e.g., organic dyes and inorganic clusters ), with notable exception of smaller systems where the HOMO-LUMO transition is symmetry forbidden . In the following section, we explore the source of such seemingly contradictory results by showing that investigating a reduced subset of the chemical compound space can lead to correlations between quantities that are generally uncorrelated.