The effective use of precision electroweak measurements

Several reasonably model-independent formulations of the implications of new physics for precision electroweak measurements have been developed over the past years, most notably by Peskin and Takeuchi, and by Altarelliet al. These formulations work by identifying a small, but useful, set of parameters through which new physics often enters into well-measured physical observables. For the theories to which such an analysis applies, this approach greatly streamlines the confrontation with the data. Since the experimentally-allowed range for these parameters has been determined from global fits to the data, theorists need only compute their predictions for these parameters to constrain their models. We summarize these methods here, together with several recent generalizations which permit applications to wider classes of new physics, and which include the original approaches as special cases.