Özet:
The purpose of this study was to investigate teachers' content knowledge - subject matter knowledge (SMK) and pedagogical content knowledge (PCK)-during teaching the slope of line in eighth grade. The study focused on two pre-service, two novice, and two experienced primary mathematics teachers’content knowledge in instruction. The study included a semi-structured pre-interview with the participants on the ways they were planning to teach, observation and video recording of lessons on slope of line, and finallya semi-structured post-interview. Instructions and interviews were transcribed and coded by open coding. The video recorded data were analyzed in terms of the units of a framework, Knowledge Quartet (KQ), and triangulated with the interview data. Findings were reported in four sections. The sections in which the findings were reported in terms of the units of the analytical framework were (i) the pre-service teachers (no official teaching experience), (ii) the novice teachers (1-3 years of teaching experience), (iii) the experiencedteachers (3-5 years of teaching experience), and finally (iv) the comparison of teachers' content knowledge. Findings were reported in terms of the four units of the framework with a comparison table among the participants.The study of the slope of lines provided a rich source to interpret teachers' content knowledge in this mathematical concept and its teaching (SMK and PCK). The study provided that foundational knowledge was significantly observed in teachers’ instruction. In addition, this type of knowledge was considerablysignificant in experienced teachers' instructions. Findings indicated also that as teachers become more experienced, they may have more robust content knowledge (SMK and PCK). As experienced teachers differed from their novice and pre-service colleagues, not much significant differences were observed between groups of novice and pre-service teachers in terms of their content knowledge of teaching slope of a line based on KQ.
