Improving the Jet Reconstruction with the Particle Flow Method; an   Introduction
  At the future electron-positron TeV linear collider, the reachable physics will be strongly dependent on the detector capability to reconstruct high energy jets in multi-jet environment. At LEP, SLD experiments, a technique combining charged tracks and calorimetric information has been used to improve the jet energy/direction reconstruction. Starting from this experience, it has been proposed to go from partial individual particle reconstruction to complete (or full) individual reconstruction. Different studies have shown that the reachable resolution is far beyond any realistic hope from calorimetric-only measurement. 
Jean-Claude Brient (LLR)