Classification accuracy comparison of 7 competing methods using 5-NN (A) and NN (B) classifiers. The proposed DIGS pathway activity inference method is compared against other pathway activity inference methods (Mean, Median, PCA and CORGs) and also genes-based methods (SG and per_pathway). Classification accuracy is summarised as average prediction rates over 50 runs of random partition of datasets into a 70% training set and a 30% testing set. With 5-NN classifier (A), it is evident that DIGS outperforms other methods by some distance as topping the chart on 6 datasets (Singh, Popovici, Desmedt, Swindell, Farmer and Pawitan) while being tied 1st on the other 2 datasets (Shipp and Yao). Prediction rates achieved by DIGS are generally high, over 80% in most datasets, which facilities its application in real world. With NN classifier (B), the same trend can be observed that prediction accuracies achieved by DIGS at least matches the state-of-the-arts methods in literature for binary disease classification problems, while consistently outperforms the competing methods for multi-phenotype problems.