  A new method is proposed for extracting limits on spin-dependent WIMP-nucleon
interaction cross sections from direct detection dark matter experiments. The
new method has the advantage that the limits on individual WIMP-proton and
WIMP-neutron cross sections for a given WIMP mass can be combined in a simple
way to give a model-independent limit on the properties of WIMPs scattering
from both protons and neutrons in the target nucleus. Extension of the
technique to the case of a target material consisting of several different
species of nuclei is discussed.
