  Several methods of statistical analysis are proposed and analyzed in
application for a specific task -- extraction of the structure functions from
the cross sections of deep inelastic interactions of any type. We formulate the
method based on the orthogonal weight functions and on an optimization
procedure of errors minimization as well as methods underlying common $\chi^2$
minimization. Effectiveness of these methods usage is analyzed by comparison of
the statistical parameters such as bias, extraction variance etc., for sample
deep inelastic scattering data set.
