Redshift difference dz = z_MASSIV − z_VVDS between the independent redshift measurements of the VVDS and MASSIV surveys for 88 galaxies in the VVDS and in the MASSIV survey (Contini et al. 2012). flags 2 are represented with circles, flags 3 and 4 with squares, and flag 9 with stars. Dashed lines identify dz = 0.0025 × (1 + z). The sigma of the redshift difference between VVDS and MASSIV redshift measurements normalized to the expansion factor (1 + z) is σ_dz = 0.00072 which translates to an individual redshift measurement uncertainty of σ_v = 153 km s^-1.