  This paper shows how to use the Kohonen algorithm to represent
multidimensional data, by exploiting the self-organizing property. It is
possible to get such maps as well for quantitative variables as for qualitative
ones, or for a mixing of both. The contents of the paper come from various
works by SAMOS-MATISSE members, in particular by E. de Bodt, B. Girard, P.
Letr\'{e}my, S. Ibbou, P. Rousset. Most of the examples have been studied with
the computation routines written by Patrick Letr\'{e}my, with the language
IML-SAS, which are available on the WEB page http://samos.univ-paris1.fr.
