We parametrize in a model-independent way possible departures from the mini
mal standard model predictions in the matter sector. We only assume the sym
metry breaking pattern of the standard model and that new particles are suf
ficiently heavy so that the symmetry is nonlinearly realized. Models with d
ynamical symmetry breaking are generically of this type. We review in effec
tive theory language to what extent the simplest models of dynamical breaki
ng are actually constrained and the assumptions going into the comparison w
ith experiment. Dynamical symmetry breaking models can be approximated at i
ntermediate energies by four-fermion operators. We present a complete class
ification of the latter when new particles appear in the usual representati
ons of the SU(2)(L) x SU(3)(c) group as well as a partial classification in
the general case. We discuss the accuracy of the four-fermion description
by matching to a simple ''fundamental'' theory. The coefficients of the eff
ective Lagrangian in the matter sector for dynamical symmetry breaking mode
ls (expressed in terms of the coefficients of the four-quark operators) are
then compared to those of models with elementary scalars (such as the mini
mal standard model). Contrary to a somewhat widespread belief, we see that
the sign of the vertex corrections is not fixed in dynamical symmetry break
ing models. This work provides the theoretical tools required to analyze, i
n a rather general setting, constraints on the matter sector of the standar
d model. [S0556-2821(99)05621-0].