This paper reports a case study of four grade 10 physical sciences teachers" PCK about graphs of motion. We used three data collection strategies, namely teachers" written accounts, captured by the Content Representation (CoRe) tool, interviews and classroom observations. We conceptualised the PCK displayed in the CoRe tool and the interview as "reported PCK" and the PCK demonstrated during lessons as "enacted PCK". These two manifestations of PCK were compared to establish the extent of agreement between reported and enacted PCK. We adopted the Topic Specific PCK (TSPCK) model as the framework that guided this study. This model describes TSPCK in terms of five components of teacher knowledge. Guided by the model, we designed two rubrics to assess these manifestations of TSPCK on a four point scale. The results of this study indicated that the reported PCK was not necessarily a reflection of the PCK enacted during teaching. The levels of PCK in the components were seldom higher in the enacted PCK, but tended to be similar or lower than in the reported PCK. The study implies that the enactment of PCK should be emphasized in teacher education.

It has recently been suggested that pedagogical content knowledge (PCK) has a concept-specific nature, beyond the topic-specific level of PCK. This paper reports a case study of three pre-service teachers' reported PCK about three fundamental concepts within the topic of electrostatics, namely electrostatic force, electric field and electric field strength. The aim of the study was to compare the quality of the PCK of each of the individual participants across these fundamental concepts. Data was collected using a content representation tool and a lesson planning form prescribed by the participants' teacher training institution. A topic-specific PCK model was adopted as the framework for this study. The model asserts that the content of a particular topic is transformed for instruction through five components, namely learners' prior knowledge, curricular saliency, what is difficult to teach, representations including analogies and conceptual teaching strategies. Guided by the model, we designed a rubric to assess the concept-specific PCK of the participants on a four-point scale. The results of the study indicated that the PCK of the participants varied across the fundamental concepts of electrostatics, with each participant reporting better PCK for a different concept. The results of the study imply that describing PCK at concept level is appropriate and recommend that PCK should be strengthened at concept level during teacher training to ensure that it develops across all of the concepts within a topic.

This paper reports a case study that explored teachers’ dynamic pedagogical content knowledge (PCK) across three big ideas of electrostatics namely the electrostatic force, electric field, and electric field strength. Two pre-service and two in-service teachers participated in the study. The refined consensus model of PCK was adopted as the theoretical framework for the study. We studied PCK as enacted during classroom teaching using observations and interviews. Data was analyzed alongside a four-point scale grand PCK rubric used to score the competence of the teachers for every big idea. The results showed that PCK of the teachers varied across the big ideas, which is attributed to the nature of concepts, as well as teachers’ content knowledge in each. The findings imply that pre-service teacher education programs should involve focus on teaching specific concepts to support the development of holistic PCK for a topic.