The purpose of this study was to investigate teachers' subject matter knowledge relevant to the teaching of informal line of best fit. Task-based interviews were conducted with nineteen pre-service and in-service mathematics teachers. The results include descriptions and categorizations of teachers' conceptions, criteria for placement, accuracy of…

Due to changes in Dutch mathematics education, teachers are expected to use new teaching methods such as enquiry-based teaching. In this study, we investigate how teachers design, implement and evaluate new methods for statistics teaching for 7th-graders during a professional development trajectory based on peer collaboration. We monitored…