Pre- and post-tests and interviews of college students, many of them pre-service teachers, revealed naïve views of science as objective and certain rather than socially-constructed and tentative. Even after taking one or more history of science courses, few of them (only 14-28%) changed their views, and then only with regards to one or two items explicitly addressed in the course. The investigators therefore recommend that history of science courses explicitly address the nature of science in detail, teach students to regard historical materials in context (from the perspective of the people of that period), and to explain the relevance of the historical science they are studying with modern science.