Online example-based assessment as a resource for teaching about quadrilaterals

We used an assessment platform to study the potential of rich student data obtained online to influence classroom instruction and help teachers respond to students’ needs. The article focuses on technology-based formative assessment in the course of teaching a unit on quadrilaterals. We studied example-eliciting tasks, requiring students to determine the truth of a given claim and to use interactive diagrams to construct examples to support their answer. Our aim was to teach the concept of parallelogram by exploring students’ concept images and responding adequately to their submissions. A group of 11-year-old students studied the unit as part of their geometry curriculum. We used an assessment platform, which provides tools designed to monitor examples produced by students interacting with a dynamic geometry environment and to characterize critical and non-critical attributes of the submitted constructions. We present the teaching decisions made by the teacher (the first author), who used automatic feedback on the characteristics of three assessment tasks.