ground-based determinations of Sérsic indices are sufficient to broadly distinguish populations with high average values from those with low average values. The lower (binned) distribution compares the mean Sérsic indices, binned as a function of $n_{\rm
        CANDELS}$. Open symbols denote mean values determined from fewer than 5 galaxies. There are deviations from a 1:1 relation, but no evidence for a systematic bias in ground-based Sérsic determinations with spectral type. Galaxies shown have photometric redshifts in the range $1<z<2$ and stellar masses with log (M$_{\ast}$/M$_{\sun}$)$>10$, to match the samples used in this work. []{data-label="fig:sersic-test"}](ntest_bin_mean.pdf "fig:"){width="0.9\linewidth"}

CANDELS-UDS
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Throughout this work we compare our ground-based determinations of galaxy size and Sérsic index with measurements from the Hubble Space Telescope (HST) CANDELS survey (Grogin et al. 2011; Koekemoer et al. 2011), using measurements provided in van der Wel et al. (2012). The UDS is one of the three targets for the CANDELS Wide survey, with imaging in the $J$ and $H$ bands taken with the Wide Field Camera 3 (WFC3). The CANDELS imaging covers only $\sim$7% of the UDS field ($\sim$9% of the area used in our analysis), but this is sufficient to provide an independent test and calibration for our ground-based structural 