Status of Fragmentation Models

Phenomenological models of multiparticle production have become increasingly important for the interpretation of experimental data in high energy physics. The evolution of these models fills a gap left open by the present limited theoretical understanding of the hadronization process, i.e. the transformation of outgoing colored partons into color singlet hadrons. The three main schools of thought, string fragmentation, cluster fragmentation and independent fragmentation, are presented in this paper. Included are discussions on similarities and differences, successes and failures, and recent developments. Perturbative QCD aspects with strong ties to the multiparticle production picture are also covered, in particular parton showers. An account is given of experience gained in the comparison between data and models. Since fragmentation studies are particularly well developed for e+e− annihilation events, this field is described in detail. A few comments are also presented for leptoproduction and hadron collisions