This article discusses our investigation regarding nature of science (NOS) implementations and epistemological beliefs within an undergraduate introductory astronomy course. The five year study consists of two years of baseline data in which no explicit use of NOS material was implemented, then three years of subsequent data in which specific NOS material was integrated into the classroom. Our original study covered two years of baseline data and one year of treatment data. Two additional years of treatment course data have revealed intriguing new insights into our students’ epistemic belief structure. To monitor the evolution of belief structures across each semester we used student pre-post data on the Epistemological Beliefs About the Physical Sciences (EBAPS) assessment. The collected data were also partitioned and analyzed according to the following variables: college (Letters of Science, Business, Education, etc.), degree (BA or BS), status (freshman, sophomore, etc.), and gender (male or female). We find that the treatment course no longer undergoes significant overall epistemic deterioration after a semester of instruction. We also acquire a more detailed analysis of these findings utilizing the aforementioned variables. Most notably, we see that this intervention had a pronounced positive impact on males and on students within the college of Education, Arts & Architecture, and those with no concentration. Lastly, whether or not students believe their ability to learn science is innate or malleable did not seem to change, remaining a rigid construct with student epistemologies.