Bridging the expertise gap: a comparative case study of pedagogical scientific language knowledge between an experienced and a novice teacher

In school settings, language plays a crucial role in the transmission of knowledge. This case study describes and compares the Pedagogical Scientific Language Knowledge (PSLK) of a novice and an experienced junior high school chemistry teacher. Data were collected from 40 classroom observations, as well as semi-structured and post-class interviews. Using the PSLK framework, we evaluated the teachers’ performances across PSLK elements. Results revealed distinct PSLK characteristics and teaching differences between the two educators. The experienced teacher demonstrated effective integration and adaptive optimization of scientific language strategies, including multimodal scaffolding, conceptual-language synergy, and contextualization in real-life situations. In contrast, the novice teacher adopted fragmented and formulaic approaches, characterized by inconsistent terminology use, superficial connections between concepts and language, and limited adaptability in teaching strategies. These findings underscore the need for teacher education programs to explicitly foster the systematic integration and adaptive use of PSLK to support the professional growth of novice teachers.