Developed by American political scientist and systems analysist Charles A. McClelland, the World Event/Interaction Survey (WEIS) was a pioneering application of Systems Theory to international relations. It was a record of the flow of action and response between countries (as well as non-governmental actors, e.g., NATO) reflected in public events reported daily in The New York Times from January 1966 through December 1978. The unit of analysis in the dataset was the event/interaction, referring to words and deeds communicated between nations, such as threats of military force. Each event/interaction was a daily report of an international event. For each event the actor, target, date, action category, and arena were coded as well as a brief textual description. 98,043 events were included in the dataset.
Charles A. McClelland, World Event/Interaction Survey (ICPSR 5211). Ann Arbor, Michigan: Inter-University Consortium for Political and Social Research, Ann Arbor, 1976.