  We compute the anomalous dimensions of a set of composite operators which
involve derivatives at four loops in MSbar in phi^4 theory as a function of the
operator moment n. These operators are similar to the twist-2 operators which
arise in QCD in the operator product expansion in deep inelastic scattering. By
regarding their inverse Mellin transform as being equivalent to the DGLAP
splitting functions we explore to what extent taking a restricted set of
operator moments can give a good approximation to the exact four loop result.
