We consider documents as the results of dynamic processes of documentary fragments' compositions. We have experi- enced that once a substantial number of associations exist, users need some synoptic views. One possible way of provid- ing such views relies in the organization of associations into relevant subsets that we call "dimensions". Thus, dimen- sions offer orders along which a documentary archive can be explored. Many works have proposed efficient ways of pre- senting combinations of dimensions through graphical user interfaces. Moreover, there are studies on the structural properties of dimensional hypertexts. However, the prob- lem of the origins and evolution of dimensions has not yet received a similar attention. Thus, we propose a mechanism for helping users in the construction of dimensions. Our pro- posal has been implemented (in the context of DINAH, our multistructured documents framework) and validated with users from the humanities field. A poster will be presented and a demonstration of our prototype will be available.