Elaborating on the unexpected: a primary teacher's responses to students’ ideas on length measurement

This qualitative case study examines the kind of elaborations provided by an in-service primary teacher in response to students' unexpected ideas related to length measurement. Using Abdulhamid and Venkat's Elaboration Framework, 10 consecutive lessons were analysed to identify instructional episodes - breakdowns, sophistications and individuations/ collectivisations - and to reveal the nature and depth of the teacher's elaborations. Data sources included field notes, video recordings of lesson hours and audio recordings of interviews with the teacher. Findings revealed that the unexpected moments resulted from an incorrect example measured in kilometres, a false statement about relationships between length measurement units, a correct explanation of the reasoning behind conversion rules of length measurement units and the incorrect usage of millimetres. Furthermore, it was found that the teacher's elaborations varied across episodes, revealing distinct patterns in how she supported or extended student thinking. These findings can provide implications for teacher educators to help pre-service teachers notice and elaborate on students' ideas.