Coincidence measurements with high energy electrons

I discuss topics that fall under the heading of coincidence measurements with high energy transfer ω or high momentum transfer q or both. High ω measurements lead us into the energy domain where meson creation dominates the photon absorption process and where meson and isobar propagation and decay in the nuclear medium can be studied. High q measurements lead us into the small distance domain where one hopes to study features of the nucleon-nucleon interaction that are obscure at longer wave lengths. (orig./HSI)