ABSTRACT
Ostrom's theory on the sustainable governance of commons had so far mainly been applied to small local rural resource systems. A main idea in the research design for the work in ROCSET was to understand whether her theory on collective action is transferrable to more complex bigger urban resource systems with less clearly defined boundaries. The green spaces resource system across the 29 European cities from which the qualitative data comes is considered as a one-case qualitative observational case study analysing within-case synchronic spatial variation. Before going to the cities, the field researchers conducted desktop research and contacted the keyholders to compile a preliminary list of actors according to the field research design following specific rules for the type of actors to be contacted. For carving out the knowledge of local experts, it is common to draw on individual interviews which are mostly based on an interview guide.
