  The role of 5-quark operators in extracting the nucleon excited state
spectrum via correlation matrix techniques is explored. In particular, the
coupling of meson-baryon operators to nucleon resonance states and scattering
states is studied. Results are presented for 2+1 flavour dynamical ensembles in
both the positive and negative parity channels. Fitting a single-state ansatz
to the eigenstate-projected correlators provides robust energies for the
low-lying spectrum that are essentially invariant across a variety of different
operator bases. In particular, the resonant state energies obtained both with
and without the use of meson-baryon operators agree, demonstrating that
resonance energies can be reliably extracted solely using 3-quark operators.
