A process is disclosed for retrieving information in large heterogeneous data bases, wherein information retrieval through visual querying/browsing is supported by dynamic taxonomies; the process comprises the steps of: initially showing a complete taxonomy for the retrieval; refining the retrieval through a selection of subsets of interest, where the refining is performed by selecting concepts in the taxonomy and combining them through Boolean operations; showing a reduced taxonomy for the selected set; and further refining the retrieval through an iterative execution of the refining and showing steps.