Left panel: distribution of observed, but trending corrected, velocity dispersions between 10 and 40 kpc from NGC 3311 (thick black line) compared to the average distribution of five million realisations of mock distributions that consider the observational errors only (grey thin line). Right panel: distribution of five million p-values from the Anderson-Darling test, with the vertical grey line indicating the 5% significance level. The significance of an intrinsic scatter in the observed σ_LOS distribution is 4.8σ.