  We present the first results of a new global next-to-leading order analysis
of spin-dependent parton distribution functions from the most recent world data
on inclusive polarized deep-inelastic scattering, focusing in particular on the
large-x and low-Q^2 regions. By directly fitting polarization asymmetries we
eliminate biases introduced by using polarized structure function data
extracted under nonuniform assumptions for the unpolarized structure functions.
For analysis of the large-x data we implement nuclear smearing corrections for
deuterium and 3He nuclei, and systematically include target mass and higher
twist corrections to the g_1 and g_2 structure functions at low Q^2. We also
explore the effects of Q^2 and W^2 cuts in the data sets, and the potential
impact of future data on the behavior of the spin-dependent parton
distributions at intermediate and large x.
