We train nine different RF/ECFP4 models using training sets ranging in size from 100 to 150k molecules and test the performance using a test set of 5k molecules. The RMSE is shown in Figure and b and suggests that the error is converged for the largest training set and that the model is as good as it is going to get. We first focus on the results from this model since that separates any issues related to incomplete training from any issues intrinsic to the XAI methodology.