A Additional Experiments

A.1 Estimating Test Robust Accuracy Instead of estimating the robust generalization gap, one might expect the analysis on the relationship between test robust accuracy and the measures. In this regard, we investigate the correlation between the measures and the test robust accuracy 1 E(w; ϵ, D) on the test dataset D instead of the robust generalization gap g(w). Figure 1 illustrates the difference in total τ when the robust generalization gap and the test robust accuracy are used as the target variable for correlation analysis. Figure 6: Comparison of the total τ when the robust generalization g(w) (yellow) and the test robust accuracy 1 E(w; ϵ, D) (blue) are used as the target variables for correlation analysis. Although we observe some different behavior of measures, we find that estimating the test robust accuracy can be more challenging.