The objective of this study is to provide in-service teachers an opportunity to become familiar with the controversial nature of progress in science (growth of knowledge) and its implications for research methodology in education. The study is based on 41 participants who had registered for a nine-week course on Methodology of Investigation in Education, as part of their Master’s degree program. The course is based on 20 readings drawing upon a history and philosophy of science perspective (positivism, constructivism, Popper, Kuhn, Lakatos) and its implications for educational research. Course activities included written reports, class room discussions based on participants’ presentations, and written exams. Based on the results obtained it was concluded that: (a) participants were able to understand the basic ideas of constructivist philosophy and its pedagogical implications; (b) the role of behavioural objectives in actual educational practice was questioned; (c) integration of qualitative and quantitative research methods was considered to be an alternative to the current debate about the replacement of one method by the other; (d) participants considered the dilemma of evaluating students based on what they have learned or what they should have learned, within the social constructivist framework and generally favoured the former; and (e) most of the participants were reluctant to accept constructivism as a form of positivism, a controversial thesis that is gaining support in the research literature. Given the importance of alternative approaches to growth and meaning of knowledge, it is important that teachers be aware of conflicting situations in the classroom that refer to: objectivity, scientific method, qualitative-quantitative methods, relationship between method and problem, evaluation, and a critical appreciation of constructivism.