Binned Kepler photometry (blue dots) corresponding to three 500-KOI realizations (without replacement) from the above period–radius valley (APRV) population. From this, we see significant sensitivity to systematic noise across realizations. As refraction effects are expected to be symmetric, we have binned the pre/post transit data, as to reduce the point-to-point error. Regardless of systematic variability, the refraction effect is distinguishable near ingress/egress in each realization.