  We provide a direct prescription for computing the mixing among gauge
invariant operators in N=4 SYM. Our approach is based on the action of the
superalgebra on the states of the theory and thus it can be also applied to
resolve the mixing in the dual string description. As an example, we focus on
the supermultiplet containing the BMN operators with two impurities. On the
field theory side, we derive the leading planar quantum corrections to the
naive expression of the highest weight state. Then we use the same prescription
in the BMN limit of the AdS5xS5 string theory and derive the form of the
2-impurity highest weight state. The string expression matches nicely the SYM
result and provides a prediction for the mixing due to higher order quantum
corrections in field theory.
