We also evaluated the impact of the applicability domain AD selection for the assessment of the model coverage of the chemicals space. To perform such assessment, we calculated the leverage for full descriptor space, QSAR regression model descriptors, and the direct classification model descriptors. Figure for acute fish toxicity) and the chemicals within the AD of the training set (i.e. the full descriptor space) a good level of overlap is observed. This is not the case when looking at the model specific ADs, implying an extrapolation with a much larger level of prediction error.