Proton and neutron elastic scattering between 80 and 1000 MeV

First, a review of the available experimental data is made for nucleon nucleus elastic scattering in the intermediate-energy regime (which, in nuclear physics, conventionally ranges from pion production threshold up to approx. 1 GeV. Secondly, a discussion of the description of these data in terms of conventional optical-model phenomenology, i.e., the standard optical model based on Woods-Saxon potentials. Thirdly, the failures are described for the standard optical model and improvements of the phenomenology. 33 references, 31 figures.