This paper presents an analysis of three teachers' "ordinary" class sessions integrating historical elements of science in their teaching: one a teacher of physics and chemistry and two teachers of biology and geology. It explores what prompts these teachers to integrate the history of science into their lessons, the functions they attribute to such history, the degree to which historical and scientific elements are interwoven into the tasks proposed to the students, and the types of knowledge these tasks aim to develop among students. To categorize a typology of the different knowledge areas targeted in science classes, we designed a framework of historical epistemology in order to parameterize a common scenario using the lexical analysis tool Tropes, which was then implemented to analyze the teachers' discourse during their class sessions. To study their ordinary practices, we adopted a double didactic and ergonomic framework approach. The analyses present the contrasting practices employed by three teachers in integrating historical aspects and identify logics of action specific to each teacher. For one of the teachers, the logic of action was shaped by the institutional framework, addressing the prescribed epistemological focus. For the other two teachers, the logic of action was induced by both the current socio-cultural issues and their own social commitment. The purpose of this study was to test general tools for analyzing teaching practices. Our methodology of knowledge categorization appears robust for the purpose of analyzing ordinary practices in integrating the history of science in science classroom sessions.