Neutrino mixing phenomenology

We review recent topics in the phenomenology of three and four neutrino mixing, with emphasis on the status of solar νe oscillations after the first Sudbury Neutrino Observatory (SNO) measurements, and on the status of atmospheric νμ oscillations after the recent indications from the KEK-to-Kamioka (K2K) experiment. The three-neutrino mixing scenario emerges as a consistent interpretation of solar, atmospheric, and reactor data. Conversely, the inclusion of LSND accelerator data in an extended four-neutrino scenario generates a “tension” between data subsets in global fits. Prospects for improving our current picture of ν mixing are briefly reviewed.