The view is advocated that to preserve a deductivist account of science against recent criticism, it is necessary to incorporate experimental error, or imprecision, in the deductive structure. The sources of imprecision in empirical variables are analyzed, and the notion of conceptual imprecision introduced and illustrated. This is then used to clarify the notion of the acceptable range of a functional law. It is further shown that imprecision may be ascribed to parameters in laws and theories without rendering the deductive (...) structure untestable. It is claimed that this analysis explicates the relation between laws and theories in a way that invalidates certain arguments against its deductive nature. (shrink)