imho activity diagrams are one of the diagrams provided by the uml which is an omg standard not related to utrecht university definition though it may seem similar on the surface but there are many variants of these diagrams e g workflow diagrams workflow nets and even some dialects of business process modeling are graphically similar the definition given here is not 'activity diagrams' which is sort of a reserved keyword for the definition of omg so moving the text to process data diagram seems a very good idea and would satisfy me fully or even leaving it where it is in metadata modeling if that is the term they use to refer to this kind of models and removing the redundant text from metamodeling page as i initially suggested hmm took out my hatchet and did it i think what went wrong is the interpretation of the discussion at the top of this discussion page people were complaining that metamodeling page was polluted by utrecht definition of the term and that by 'squatting' the term some information on the more generally accepted definition of the term ended up on this metamodeling technique page but i think the more generally useful info was extracted from that page already the merge was suggested as a way of providing an example provided it is very clear this is not the definition of metamodeling to conclude if the page metadata modeling contains the description of this modeling formalism i suggest we cut it from the text of this page and maybe just add a see also pointing to the other page cheers