Actors coordinate their cooperative efforts by acting on the evidence of work previously accomplished. The paper introduces, on the basis of a field study, the concept of stigmergy to the analysis of coordinative practices in architectural work. It distinguishes between practices of stigmergy and articulation work. Stigmergy is understood as coordination achieved by acting directly on the evidence of work previously accomplished and articulation work is understood as second order efforts to coordinate collaborative work. Furthermore, this leads to a distinction between representational artifacts associated with practices of stigmergy and coordination mechanisms in the service of articulation work. Categories and Subject Descriptors K.4.3 [Organizational Impacts]: Computer-supported collaborative work General Terms Design, Human Factors, Theory Keywords Coordination, cooperative work, stigmergy, articulation work, architectural work.