In many real world applications, values of some variables are organized in taxonomies, i.e. there exists a hierarchy among the different values which can be taken by the variable.

In this paper, we investigate the use of these taxonomies in two basic processes in statistical data analysis : construction of barcharts of qualitative variables, and characterization of classes of individuals by qualitative variables.

Different problems appear regarding to this approach and are described in this paper : storage management of arrays of data with taxonomic qualitative variables, extension of the standard concepts of barchart and class characterization, and graphical representation of results.

To demonstrate the effectiveness of the approach, a prototype has been developed, combining two tools : the SPLUS language for data management and statistical computations, and the VCG tool for easy visualization of results.

The prototype has been applied to a dataset describing work accidents.

This dataset has been provided by the Service Général de Médecine de Contrôle (SGMC) and features two taxonomic variables : one structuring injuries associated with accidents, and the other one the after-effects of accidents.