The Chemprop software 56 and SchNet software 61 used in model training are both freely available through GitHub. The constructed noise-free dataset of group additivity enthalpies is available through Zenodo. The QM9 dataset can be downloaded from the MoleculeNet website. The implementation of the Bayesian inference method for calculating nonvariance contribution is available through GitHub (github.com/cjmcgill/ensemble projection). Other scripts necessary to train the models analyzed in this work and recreate the results are provided through GitHub (github.com/cjmcgill/characterizing uncertainty scripts).