This paper shows outcomes of a research that aimed to identify the different epistemological conceptions incorporated into the professional practice of science teachers. As a result, there are, in different proportions, living in the schools, distinct epistemological conceptions, suggesting the occurrence of a paradigmatic crisis, justifying the difficulties in learning science. This research reaffirms the necessity of including studies of the epistemology and the history of science in initial teachers training courses, and adds the necessity to include also sociological studies, especially those about the curriculum, bearing in mind the social character of the construction of the knowledge in the paradigm that one wants to encourage.
Teachers' conceptions; Science teaching; Epistemology; Nature of science
