Toward a Multidimensional Science Content Knowledge Framework: An Expert Science Teacher's Uneven Development of Pedagogical Content Knowledge Through Classroom Teaching Experiences

ABSTRACT Contemporary science education advocates instruction that fully integrates the conceptual, procedural, and epistemic aspects of science. Pedagogical content knowledge (PCK) is the unique knowledge that teachers use to make content accessible to students. Few studies examine teachers' development of PCK for teaching conceptual, procedural, and epistemic ideas simultaneously. This qualitative case study explored the development of an expert science teacher's PCK across the plan–teach–reflect pedagogical cycle and its impact on student learning. Our conceptual framework drew on the Refined Consensus Model of PCK, which differentiates between pPCK (personal knowledge held by the teacher) and ePCK (specific knowledge and skills utilized while planning, teaching, and reflecting on a lesson), along with the multidimensional aspects of science content knowledge. Data from multiple sources, including teacher interviews, video‐recorded lessons, classroom artifacts, and student focus group interviews, were used to reveal the teacher's PCK development and its impact on student learning. Data analysis revealed several features about the expert teacher's PCK and its development: (a) The teacher's PCK extended beyond conceptual ideas to include procedural and epistemic ideas, based on his beliefs about the nature of science; (b) The teacher's PCK developed through classroom teaching experiences, facilitated by his deliberate attention to eliciting and responding to evidence of student thinking in classroom assessments; (c) The teacher's PCK development was uneven, with greater growth in PCK for teaching conceptual and procedural than epistemic ideas. Most of the students interviewed reported learning conceptual and procedural ideas through the lesson activities, reflecting the impact of the teacher's PCK, although few reported learning epistemic ideas. The findings' implications for teacher education to enhance PCK development through classroom teaching experiences are discussed.