Purity vs. completeness mean values for the membership assignments. For each cluster galaxies brighter than H_∗(z_p) + 1.5 and with a projected distance from the cluster center not greater than r₂₀₀ are considered. Different colors refer to different statistical redshift accuracy σ(z) = σ₀(1 + z). Dots show the mean values of both completeness and purity for galaxies with P_mem>P_thr, as indicated in the label. P_thr increases from the right to the left. The errors in the mean values are within the dot size.