How much do they know about 3D objects. Using authentic assessment to inform teaching practice

Although geometric reasoning is recognised as a key component for promoting STEM disciplines, very little research has been done on its promotion in middle years in Australia. There have been few studies on how to teach students to reason about three-dimensional (3D) objects. Fanned by a need to ensure authentic achievement, assessment for learning has been the centre of much research effort. It is characterised by using evidence-based data to inform teaching and learning. This chapter presents a geometric thinking model, consisting of visualisation, representation, and language and discourse as key to supporting geometric reasoning. A total of 775 Year 4 to 10 students completed a task based on reasoning about 3D objects. Analysis of results show that the thinking model can assist in identifying student knowledge and help shape learning goals that support reasoning.