Event Catalogs as Theories

All empirical social research rests, at least implicitly, on not one but two theories: a theory explaining the phenomenon under study, another theory explaining the generation of evidence concerning the phenomenon. The two theories necessarily interact, setting important constraints on each other. The second theory answers questions about how the phenomenon leaves traces, how analysts can observe those traces, and how analysts can reconstruct attributes, elements, causes, and effects of the phenomenon from those traces. As employed in studies of contentious politics, event catalogs raise all these questions. Competing conceptions of the phenomenon under study as protest, as collective violence, as collective action, as conflict, and as contentious claim-making imply different measurement strategies. The strategy of aggregation follows plausibly from identification of the phenomenon as protest or violence, the strategy of incidence from most of the competing conceptions, the strategy of internal regularities only from treatments of the crucial phenomenon as collective action, conflict, or contentious claim-making.