|dc.description.abstract||Research on teacher expertise has identified pedagogical content knowledge (PCK) as the most important factor impacting student progress (Neumann, Kind & Harms, 2019; Park & Chen, 2012) and supported its recognition in teacher practice (Kind & Chan, 2019). Since the recognition of PCK as something that teachers possess, there has been theorizing and research into its nature, its components, and the relationship among these components. To address such issues, two international summits were organized in 2012 and 2016. The key outputs of these summits were theoretical consensus models of PCK (Carlson & Daehler, 2019; Gess-Newsome, 2015). This study builds on novel emerging ideas in the first PCK consensus model (Gess-Newsome, 2015). These consensus models stressed the need for examination of PCK in classroom practices. Researchers have argued for research to understand teachers’ PCK in their practice, with the ultimate goal of the enhancement of students’ learning (Abell, 2007; Barendsen & Henze, 2019; Lee, 2020). This study then had the aim to examine experienced science teachers’ PCK during their classroom practices when they taught a chemistry topic to Year 10 students in New Zealand.
A case study approach was adopted for an in-depth examination of these teachers’ practices (e.g. Cohen, Manion, & Morrison, 2018; Yin, 2009). The sample of this study was two experienced science teachers who were selected by the convenient sampling technique. The data were collected from teachers only. The data were gathered through a pre-topic questionnaire, document analysis, follow-up lesson interviews, follow-up topic interviews, and classroom observations including video recordings of lessons. Each class lesson within a 12 lesson topic for each teacher was observed and video-recorded. The lesson follow-up interviews were conducted after each lesson and follow-up topic interviews were conducted after completion of the topic. A conceptual and analytical framework was developed to interpret and analyze the data using the knowledge components of the Consensus Model-2015 (Gess-Newsome, 2015). Data were analyzed systematically. First, recorded data from observations and interviews were transcribed, and where appropriate, validated by the participants. Second, all data were imported into NVivo for analysis. Data were coded by using deductive (using aspects of the Consensus Model) and inductive approaches. The codes were grouped into themes and considered.
The analyzed data helped to illustrate each teacher’s PCK. Each teaching episode or event was analyzed for knowledge components when they identified as prominent in teaching. This analysis identified knowledge components in the form of combinations in their teaching which reflects that PCK is a product of combinations of knowledge components. Significantly, this study indicated that there were four different types of combinations of knowledge components in their teaching. The data show that the two teachers conducted their teaching in a similar situation using different combinations of knowledge components. These findings contribute to understanding the nature of the relationship of knowledge components of PCK, which was not clear in previous PCK models. The diagrammatic representation of teachers’ knowledge combinations within PCK in this study can help to visualize teachers’ PCK and be used for teachers’ self-evaluation, teacher education, and further research into PCK in teaching practice.||