  There is currently much interest in the possible presence of
intermediate-mass black holes in the cores of globular clusters. Based on
theoretical arguments and simulation results it has previously been suggested
that a large core radius -- or particularly a large ratio of the core radius to
half-mass radius -- is a promising indicator for finding such a black hole in a
star cluster. In this study N-body models of 100000 stars with and without
primordial binaries are used to investigate the long-term structural evolution
of star clusters. Importantly, the simulation data is analysed using the same
processes by which structural parameters are extracted from observed star
clusters. This gives a ratio of the core and half-mass (or half-light) radii
that is directly comparable to the Galactic globular cluster sample. As a
result, it is shown that the ratios observed for the bulk of this sample can be
explained without the need for an intermediate-mass black hole. Furthermore, it
is possible that clusters with large core to half-light radius ratios harbour a
black-hole binary (comprised of stellar mass black holes) rather than a single
massive black hole. This work does not rule out the existence of
intermediate-mass black holes in the cores of at least some star clusters.
