and halo stars (Yoshii 1982; Preston, Shectman, & Beers 1991; Morrison 1993), (e) tests for the existence of a putative “counter-rotating” halo component beyond 4–5 kpc from the plane (Majewski 1992; Wilhelm 1995; Carney et al. 1996; Wilhelm et al. 1996; Zinn 1996; Carney 1999), (f) measures of the local halo velocity ellipsoid for comparison with the derived ellipsoid for more distant halo stars (Sommer-Larsen et al. 1997), and (g) derivation of a reliable RR Lyrae absolute magnitude estimate based on statistical parallax analyses (Layden et al. 1996; Fernley et al. 1998; Popowski & Gould 1998). As more extensive searches are carried out for evidence of past (and present) mergers of smaller galaxies with the Milky Way (e.g., Preston, Beers, & Shectman 1994; Harding et al. 1998; Helmi & White 1999; Majewski 1999), it is of equal importance to obtain secure knowledge of the “global” Galactic kinematic properties, so that deviations from the expected behavior can be reliably assessed.

To confidently address the above issues (and many others) stars chosen as kinematic tracers should be identified in a manner which does [*not*]{} depend on a kinematic selection criterion itself. Although it may be possible to statistically correct for an input 