Significant progress has been made over the past several years in developing energy‐ and density‐dependent effective interactions and optical potentials based on free nucleon‐nucleon potentials. This leads to the hope that the nucleon‐scattering reaction mechanism may be well enough known to probe details of nuclear spectroscopy (i.e., transition densities) more accurately than with purely phenomenological approaches. Of particular interest to this conference is the possibility of separating neutron and proton transition densities by comparing proton and neutron scattering, which can be done reliably only if the isovector parts of the effective interaction are well known. This paper attempts to assess the accuracy of presently available interactions through comparisons with elastic and inelastic scattering over a wide mass range, and also with the (p,n) isobaric‐analog reaction. Particular emphasis has been placed on the isovector parts of the interaction and on Coulomb corrections by comparing proton and neutron scattering on the same targets. In a number of cases, precise neutron data have been measured to facilitate these comparisons.