What is Instructional Model

The focus of this chapter is on elementary preservice teachers' (PSTs') use of justification in problem-solving contexts based on a semester algebra course designed for elementary education mathematics minors. Formative assessment and digital tools facilitated the development of PSTs' understanding and use of justification in algebraic topics. The instructional model used includes the following components: negotiating a “taken-as-shared” justification rubric criteria; engaging in problem solving; preparing, digitally recording, and posting justification videos to the Cloud; and finally, listening and sharing descriptive feedback on the posted videos. VoiceThread was the digital venue for the preservice teachers to listen to their peers' justifications and post descriptive feedback. Findings from an analysis of a group focus on the PSTs' peer- and self-feedback as it developed through a semester and the PSTs' ability to provide a range of descriptive feedback with the potential to promote growth in the understanding and use of mathematical justification.