Based on Bayesian Active Learning by Disagreement (BALD) , the left term represents the entropy of the model predictions (uncertainty) and the right term represents the expected value of the entropy of the model predictions for each draw of the model parameters (i.e., 'disagreement' between the different models in the ensemble) . To have low mutual information, the model must have many ways of explaining the data with high certainty, i.e., low uncertainty and high disagreement.