  It has been known for a long time that the clustering of galaxies changes as
a function of galaxy type. This galaxy bias acts as a hindrance to the
extraction of cosmological information from the galaxy power spectrum or
correlation function. Theoretical arguments show that a change in the amplitude
of the clustering between galaxies and mass on large-scales is unavoidable, but
cosmological information can be easily extracted from the shape of the power
spectrum or correlation function if this bias is independent of scale.
Scale-dependent bias is generally small on large scales, k<0.1 h.Mpc^{-1}, but
on smaller scales can affect the recovery of \Omega_m.h from the measured shape
of the clustering signal, and have a small effect on the Baryon Acoustic
Oscillations. In this paper we investigate the transition from
scale-independent to scale-dependent galaxy bias as a function of galaxy
population. We use the Sloan Digital Sky Survey DR5 sample to fit various
models, which attempt to parametrise the turn-off from scale-independent
behaviour. For blue galaxies, we find that the strength of the turn-off is
strongly dependent on galaxy luminosity, with stronger scale-dependent bias on
larger scales for more luminous galaxies. For red galaxies, the
scale-dependence is a weaker function of luminosity. Such trends need to be
modelled in order to optimally extract the information available in future
surveys, and can help with the design of such surveys.
