Global ratios between correlation functions along the directions parallel and perpendicular to the central group projected major axis (ω_∥/ω_⊥). Two different ratios are computed by counting pairs split into the one- and two-halo clustering regimes (left- and right-hand panels, respectively). The open symbols represent the results obtained from real observational data. Filled symbols show the corresponding results obtained from the SDSS mock catalogue. The horizontal dashed lines indicate the unit ratio (no anisotropy).