Differences in the median values of ΔO/H between the interacting and control samples at different aperture sizes. Left: aperture sizes are measured in arcsecs. Right: aperture scales are measured in effective radius. The dashed line represents the difference reported by Ellison et al. (2008). Errors bars are determined using bootstrapping in both samples. On any of the scales, the differences reach the values found in single-fiber spectrocopic studies.