This article addresses the study of document typology in the personal archives of scientists and its importance in the history of science studies and for the archivist's work. A brief history is presented of diplomatic to typological information, emphasizing that identifying document production activity as essential for its classification. The article illustrates personal archive characteristics as regards the diversity of documental types and, in particular, those belonging to physicists. Furthermore, it presents five examples of documental types found in the archives of physicists as examples of research in progress. It also highlights the elaboration of a glossary of different documental kinds and types found in the private archives of Museum of Astronomy and Related Sciences in Rio de Janeiro.