  Practical quantum state tomography is usually performed by carrying out
repeated measurements on many copies of a given state. The accuracy of the
reconstruction depends strongly on the dimensionality of the system and the
number of copies used for the measurements. We investigate the accuracy of an
experimental implementation of a minimal and optimal tomography scheme for one-
and two-qubit states encoded in the polarization of photons. A suitable
statistical model for the attainable accuracy is introduced.
