  The purpose of this contribution is to stress the great importance of
polarization observables for the study of nucleon resonances, in particular in
the case of deuteron and proton probes. Polarization observables play a unique
role in signing the reaction mechanism and bring new information in the
microscopic description of baryon resonances. We will calculate the relevant
polarization observables, for $p+d$- and $p+\alpha$-collisions, in case of
inclusive reactions and for some selected exclusive channels.
