(ANN and M5P). The above observations again validate the usefulness of unlabeled configurations, and strongly support to exploit unlabeled design configurations in DSE. Compared with the noAL approach, COAL outperforms it on 11 out of 14 benchmarks, for instance, on benchmarks swim and vortex COAL can reduce the MSE by about 58% of that of noAL; Compared with noSSL approach, COAL also outperforms it on 11 out of 14 benchmarks, for instance, on the benchmark vortex COAL can reduce