“…The reason is that they have dissimilar molecular structures with other chemicals in the training set (Keivanimehr et al, 2020; Yu, 2020a, 2020b). Furthermore, Figure 2 shows that there are 76 organic compounds with leverages h > h * of 0.03 (here h * is warning leverage and calculated with h * = 3 × ( p + 1)/ n , p, and n are, respectively, the numbers of descriptors and compounds in training set) (Liao et al, 2019; Liu, Bai, et al, 2020; Liu, Deng, et al, 2020; Yu et al, 2019; Yu et al, 2019). But their | σ | values are less than 3.…”