  With polarization of the cosmic microwave background (CMB) now detected, and
confirmed by several independent experiments, the next goal is to characterise
accurately its statistical properties. In these lecture notes we review the
physical motivation for pursuing CMB polarization, and the basic statistical
properties of the polarization fields. We then discuss some of the key aspects
of the analysis of CMB polarization data, focusing on the additional
complications that arise compared to temperature data due to the tensor
character of the polarization field.
