Relative distance residuals (estimated – reference) as a function of the main spectroscopic parameters T_eff, [Z/H] and log g as well as the reference distances d_ref. Top rows: comparison to the astrometric distance scale provided by the Hipparcos satellite, using the Bensby et al. (2014) FGK dwarf sample (1st row) and the APOGEE-Hipparcos giant sample (2nd row). 3rd row: APOGEE clusters. 4th row: CoRoT-APOGEE sample. 5th row: SEGUE clusters. The central dashed line is the identity line, whereas the upper and lower lines indicate deviations at the 20% level.