Fraction of true cluster members (f_true, y-axis) for galaxies brighter than H_∗(z_p) + 1.5 which membership probabilities (P_mem) reported in the x-axis are assigned to. Points are associated with at least five sources per bins. See Legend in the top left panel for the color code adopted. Different colors refer to different statistical redshift accuracy σ(z) = σ₀(1 + z). Mean values and Poisson uncertainties added in quadrature to δf_true = 3% are reported. Upper limits are at 2σ level. Different panels refer to different redshift intervals. At the top of each panel the reduced χ², the mean difference ⟨ f_true−P_mem ⟩, and the rms dispersion around the mean are reported. Upper limits are considered as true measurements when estimating ⟨ f_true−P_mem ⟩.