The Firebird
Commoner
Another good limiting case is biography. Robert Caro's work on LBJ, for example, doesn't have "data" or "experiments" in the sense that some people desire. But it's exhaustively researched and detailed.Anthropology is a social science. Far as that goes, its not super easy to do experiments for some branches of sociology either, but people don't act like studies of it are invalid (they may act like the sources of data look dodgy, but they still are neither surveys nor experiments; at best they're interviews).