Abstract
Adaptive expertise concerns the ability to respond effectively to novel and unexpected situations. This expertise is important for improving students’ cognitive engagement, understanding and participation in meaningful learning. This paper presents findings on primary teachers’ adaptive expertise in interdisciplinary mathematics and science using a video-stimulated questionnaire with multiple choice items and verbal explanations. Data were collected prior to the teachers’ planning and teaching interdisciplinary lessons. Findings showed discrepancies between responses to the items and verbal explanations, indicating gaps between their espoused and enacted adaptive expertise.