Overfitting in catalysis can occur during the optimization of catalyst properties. Researchers might use complex mathematical models to fit experimental data. If the model is too complex, it may fit the noise in the data rather than the underlying trend. Another way overfitting can occur is through high-throughput screening, where a large number of catalysts are tested under a set of conditions. If the selection criteria are too narrowly defined, the chosen catalysts might not perform well in broader applications.