Parametric information theory is applied for investigation of minimum variance boundary of the Stokes parameter estimates of a partially polarized quasi-monochromatic radiation in a polarimetric scheme with the analyzer and phase compensator in normal additive noise. Based on the analysis of the information density distributions in the factors of the rotation angle of the analyzer and phase shift of the compensator it was possible to justify the existing and found new measurement plans. The dispersion matrixes associated with these plans are found. The formulas are derived for obtaining effective estimates. The error limits of the various polarization parameters are calculated. The results of the analysis are confirmed by numerical simulation.