  Let an indirectly measurable variable be represented as a function of a
finite number of directly measurable variables . In our previous researches we:
1) represented the maximum inaccuracies of in first degree of approximation as
linear functions of the inaccuracies of ; 2) defined the spaces of the maximum
inaccuracies and we defined a dimensionless scale for quality (accuracy)
evaluation of an experiment in them; 3) introduced the maximum inaccuracies in
second degree of approximation.
  In the current paper we prove that the maximum inaccuracies of in second
degree of approximation are quadrics of the inaccuracies of and that these
forms describe certain types of quadric hypersurfaces of parabolic class.
Moreover: 1) we give a complete algebraic classification of these
hypersurfaces; 2) we define a dimensionless scale for quality (accuracy)
evaluation of the experiment given the maximum inaccuracies in second degree of
approximation.
