The Working Group for Data-Processing in Phytosociology of the International Society for Vegetation Science is now to finish its activities. Through four conferences of the Working Group at Trieste (1969), the Netherlands (1971), Prague (1973) and Montpellier (1975), during the 14th Symposium of the Society which was devoted to Basic problems and methods in phytosociology and included 12 contributions from members of the Group (Van der Maarel & Tuxen 1972; see Van der Maarel 1971), during small meetings at the Society’s Symposia in Rinteln, as well as through numerous personal contacts, the Working Group largely achieved its original aim, viz. the assimilation of computer-based data-processing in Braun-Blanquet phytosociology. Furthermore, theories and new methods were developed which are of general interest for quantitative and theoretical plant ecology.