the concept of electron correlation is fundamental to condensed matter physics, playing an important role in systems including high temperature superconductors, heavy fermions, manganite compounds with colossal magnetoresistance, transition metal compounds with metal-insulator transitions, and mesoscopic systems like quantum dots and carbon nanotubes. the dialogue between experimentalists and theoreticians presented here is an assessment of our current understanding of the field; one that sets the agenda for future work.