Contours depicting cumulative population fractions 0.08,  0.25,  0.42,  0.58,  0.75 and 0.92 for GAMA galaxy/zph-randoms catalogues on the z_phot./rand. vs. z_spec. plane, where the y-axis refers to z_phot. for galaxies and z_rand. for randoms. For randoms, z_spec. refers to the spectroscopic redshift of the parent galaxy to a clone at redshift z_rand.. Blue contours depict our windowed randoms, with window-width σ = 5 × 10⁶ (h⁻¹ Mpc)³, and orange contours are for unwindowed randoms. One clearly sees the intentional photo-z biases (Sect. 3.3) in the galaxy contours (solid black), and how the randoms (dashed colours) softly mimic them. Figure 14 shows five ‘marginals’ through this distribution for (zph-windowed randoms only), collapsing the y-axis to show n(z_spec. | z_phot.).