  We examine the momentum and energy dependence of the scattering rate of the
high temperature cuprate superconductors using angle resolved photoemission
spectroscopy. The scattering rate is of the form a + bw around the Fermi
surface for under and optimal doping. The inelastic coefficient "b" is found to
be isotropic. The elastic term, "a", however, is found to be highly anisotropic
for under and optimally doped samples, with an anisotropy which correlates with
that of the pseudogap. This is contrasted with heavily overdoped samples, which
show an isotropic scattering rate and an absence of the pseudogap above T_c. We
find this to be a generic property for both single and double layer compounds.
