Upper panel: the FoM_TOT for different subsets of correlations that are observable from a galaxy survey with galaxy shape and number density measurements. The Fisher matrix has been computed for the total data set containing all correlations, i.e. these results represent the information content of the subsets as a part of the total signal. Black dashed bars correspond to a marginalisation over N_K = N_Z = 7 nuisance parameters, grey solid bars to N_K = N_Z = 3 nuisance parameters. The labels on the abscissa indicate the different combinations of correlations used, where ϵn stands for the cross-correlations between number density and ellipticity. Lower panel: difference Δ FoM, see (48), for the same subsets as above. This difference can be understood as a measure of the depletion of information in the subsets due to the marginalisation over nuisance parameters.