Exploring the Micro-Structure of the Proton: from Form Factors to DVCS
  For a long time people made the mistake of thinking the proton was understood. New experiments, ranging from form factors to deeply virtual Compton scattering, promise a new era of highly informative studies. Among the controversial topics of the future may be such basic features as the physical size of the proton, the role of quark orbital angular momentum, and the possibility of making "femto-photographic" images of hadronic micro-structure. 
John P. Ralston and Pankaj Jain