  The next-to-next-to-leading order (NNLO) QCD analysis of the revised
experimental data of the CCFR collaboration for the $xF_3$ structure function
of the deep-inelastic scattering of neutrinos and antinuetrinos on the nucleons
is made by means of the Jacobi polynomial expansion technique. The NNLO values
of the QCD coupling constant are determined both without and with twist--4
contributions taken into account. Theoretical ambiguities of $\alpha_s$ are
fixed using the methods of the Pad\'e approximants. We observe that the [0/2]
Pad\'e approximant is more appropriate for this purpose than the [1/1] one.
