[en] Much of the information on electronic, atomic, nuclear and particle physics is obtained in scattering experiments. The inverse scattering problem is to deduce the interaction between the colliding particles, or what their constitution is, from the observed data. Inverse scattering techniques at fixed energy which have lent themselves to practical application are reviewed. Some recent applications, in particular to electron-atom scattering, are discussed. New results for e-He scattering at 30eV are presented. 45 refs., 2 tabs., 4 figs