-1.2 -1.6 -1.65 -1.4 -1.75 -1.7 -1.6 -1.8 02468 10 Costs (a) × 104 -1.8 -1.85 0246 810 × 104 Costs (b) -1.2 -1 -1.4 -1.6 02468 10 Costs (c) 0.1 0.2 × 104 0.3 -1.8 -1.6 02468 10 × 104 Costs (d) 0.4 0.5 FIGURE 6 The performance of EMTAUC with varying ratio of the whole dataset for the cheap task on (a) diabetes, (b) fourclass, (c) german, and (d) splice. -0.18 -1 -1.2 -1.4 -0.2 -0.5 -0.22 -1 -0.24 2-5 2-4 2-3 λ (a) 2-2 2-1 20 2-5 2-4 2-3 2-2 λ (b) FIGURE 7 The relationships between the penalty parameter and the average AUC value obtained by EMTAUC-SBGA on two representative datasets, where the dotted line represents the average AUC value obtained by Single-task GA, (a) diabetes, and (b) fourclass. 2-1 20 80 IEEE COMPUTATIONAL INTELLIGENCE MAGAZINE | MAY 2022 log (AUC) log (Averaged Objective Value) log (Averaged Objective Value) log (AUC) log (Averaged Objective Value) log (Averaged Objective Value)