Average error in the galaxy-bias normalisation f_b (x-axis) and f_r (y-axis). The points show as indistinguishable the errors of all galaxy samples SM1-4, BLUE, and RED together; the point styles indicate the redshift bin and what is varied. Symbols as in the figure key indicate the low-z samples, inverted symbols indicate the high-z samples (e.g. solid and open circles). The “cosmo” and “sampling p(z)” data points reuse the same galaxy samples many times with random normalisation errors. The solid line marks the estimated error for high-z samples dueto the baryon uncertainty. The fiducial cosmology is WMAP9. See text for more details.