Room temperature Hall data were obtained for Ni3Mn and Fe-Co samples that had been heat treated to produce varying amounts of atomic ordering. In Ni3Mn the values of R0* were found to change uniformly from a negative value for the well-ordered sample to a positive value for the disordered sample. In Fe-Co the values of R0* were found insensitive to the degree of atomic ordering. Since room temperature is well below the Curie point for Fe-Co, the values of R0* will be nearly identical to the ordinary Hall coefficients and therefore related to the band structure. In Ni3Mn the magnetic properties-saturation inductance and Curie point-depend strongly upon the degree of atomic ordering. For disordered Ni3Mn the Curie point is very near room temperature. It was therefore believed that the dependence of R0* upon the degree of atomic ordering was associated with a Curie point anomaly rather than a fundamental change in band structure. This hypothesis has been substantiated by preliminary measurements at 77°K (T<<Tc). At these low temperatures R0* does become negative in disordered Ni3Mn.