  B^0-anti-B^0 flavor oscillations are studied in e^+e^- annihilation data
collected with the BABAR detector at center-of-mass energies near the Y(4S)
resonance. One B is reconstructed in a hadronic or semileptonic decay mode, and
the flavor of the other B in the event is determined with a tagging algorithm
that exploits the relation between the flavor of the heavy quark and the
charges of its decay products. Tagging performance is characterized by an
efficiency e_i and a probability for mis-identification, w_i, for each tagging
category. We report a determination of the wrong-tag probabilities, w_i, and a
preliminary result for the time-dependent B^0-anti-B^0 oscillation frequency,
Delta_md = 0.512+/-0.017+/-0.022 hbar-ps^{-1}.
