  [Abridged] We use mock catalogues based on the GALICS model (Hatton et al.
03) to explore the nature of galaxy clustering observed in the SDSS. We measure
low and high order angular clustering statistic from these mock catalogues,
after selecting galaxies the same way as for observations, and compare them
directly to estimates from SDSS data. Note that we also present measurements of
S3-S5 on the SDSS DR1. We find that our model is in general good agreement with
observations in the scale/luminosity range where we can trust the predictions.
This range is found to be limited (i) by the size of the dark matter simulation
used -- which introduces finite volume effects at large scales -- and by the
mass resolution of this simulation -- which introduces incompleteness at
apparent magnitudes fainter than $r\sim 20$. We then focus on the small scale
clustering properties of galaxies and investigate the behaviour of three
different prescriptions for positioning galaxies within haloes of dark matter.
We show that galaxies are poor tracers both of DM particles or DM
sub-structures, within groups and clusters. Instead, SDSS data tells us that
the distribution of galaxies lies somewhat in between these two populations.
This confirms the general theoretical expectation from numerical simulations
and semi-analytic modelling.
