Spectroscopic redshift distributions of GAMA galaxies, binned by the mock photometric redshifts we describe in Sect. 3.3. Vertical black lines depict the bin-edges in z_phot. and solid curves give the resulting n(z_spec. | z_phot.) for galaxies. Selecting only the clones of those binned galaxies, from our ‘zph-windowed’ GAMA randoms [σ = 5 × 10⁶ (h⁻¹ Mpc)³], the randoms’ redshift distributions are then given by the dashed curves. One sees that our ‘zph-randoms’ [generated using samples from the n(z_spec. | z_phot.)’s centred on individual galaxies’ z_phot. – see Sect. 3.3] are thus able to trace the artificial photo-z biases – for example, the secondary peak at z ∼ 0.3 in the final panel, which is captured by the tail of the randoms’ n(z). These curves are equivalent to horizontal bands in Fig. 13, summed over the y-axis.