The hierarchical organization of information in astronomy or “How to organize things to find them without much effort”

Abstract A hierarchical organization scheme to facilitate the access to astronomical databases in the context of datamining is presented. The scheme was developed empirically based on the quantities stored in the database system known as VizieR at the Centre de donnees astronomiques de Strasbourg. This system of meta-information attached to the data allows answering very general queries about the catalog's content by identifying groups of similar quantities with a relatively small number of descriptors compared to the current way of naming quantities, which is essentially author-driven. Current and future applications are discussed.