  Bjorken scaling is violetd. At large $x$-values ($0.7 \lesssim x \leq 1$) the
violation is mainly attributed to $\propto 1/Q^2$ (higher-twist) corrections.
We discuss how to incorporate such corrections by using a new scaling variable
$\bar x(x,Q^2)$ which accounts for the non-perturbative effects due to the
confining parton interaction in the final state. The approach can accomodate
also the remaining QCD logarithmic corrections and the behaviour of the
$F_2(x,Q^2)$ structure functions is reproduced, in a quite natural way, within
a wide kinematical range.
