Abstract
Ever since work of Paul Feyerabend, Russell Hanson and Thomas Kuhn in the 1960s, the thesis of the theory-ladenness of scientific observation has attracted much attention both in the philosophy and the sociology of science. The main concern has always been epistemic. It was argued –or feared– that if scientific observations depend on prevalent theories, an objective empirical test of theories and hypotheses by independent observation and experience is impossible. This suggests that theories might appear to be well confirmed by observation, and yet it is not likely that they are largely true or empirically adequate. While some philosophers like Ian Hacking have argued that serious theory-dependence is less common than often assumed, sociologists such as David Bloor, Stephen Shapin, Karin Knorr-Cetina or Harry Collins have based their constructivist programs for the sociology of science on strong claims of theory-ladenness.