  Systematic effects on HI and Halpha long-slit observations make a measurement
of the inner slope of the dark matter density distribution difficult to
determine. Halos with constant density cores and ones with r^-1 profiles both
appear consistent with the data, although constant density cores generally
provide better fits. High-resolution, two-dimensional velocity fields remove
most of the systematic effects, yet as a result of noncircular and random
motions the inner slopes still cannot be accurately measured. Halo
concentration parameters provide a more useful test of cosmological models
because they are more tightly constrained by observations. The concentration
parameters for LSB galaxies appear consistent with, but on the low end of the
distribution predicted by CDM.
