BitterX and BitterPredict adopt SVM and Adaboost methods respectively, while e-Bitter implicitly integrates nine consensus models (CM01-CM09) and optionally includes 96 average models (AM01-AM96). To evaluate the performance of all the models, two types of comparisons are conducted. One is the direct comparison on the test set reported in the original works. The other is the more fair comparison on the three external test sets in the recent work of Wiener et al.