Structure of baryon resonances from hadronic and electromagnetic probes

In this talk we discuss how information on the dynamical structure of baryons can be derived from experimental data. For the lowest N* (Roper resonance) a consistent description of α-p, π-N and γ-p reveals a double structure of this resonance. New results from the SPES4π experiment at Saturne support this picture. The derived features are not in agreement with a simple constituent quark model, but are well described assuming a sound mode of a medium of quarks and antiquarks. This yields evidence for a rather complex baryon structure. To study further specific properties of higher resonances, exclusive studies of p-α scattering are planned for COSY. (orig.)