A medicinal chemist's feedback achieves similar performance as the simulated chemist's feedback in the previous section. On average, the performance increases from 0.18±0.06 to 0.52±0.15 (mean± standard error of the mean). In the best case in Figure , the average DRD2 activity evaluated by the oracle quantitative structure-activity relationship (QSAR) model increases 159% (from 0.33 to 0.85) in the generated molecules after 100 queries to the chemist.