Examining Preservice Teacher Thinking about Technology-Based Trigonometric Explorations through a Replacing, Amplifying, and Transforming Framework.

Researchers promoting the inclusion of technology for teaching and learning have recently called for the integration of mathematical technologies into the preparation of future teachers. This report analyzes the dynamic geometry sketches produced by preservice secondary mathematics teachers when investigating trigonometric relationships. We analyzed preservice teachers’ approaches to a particular task based on the extent to which the technology replaced, amplified, or transformed learning opportunities about tangent. We highlight the prominent aspects of the diagrams produced and discuss technological affordances these diagrams present for supporting preservice teachers’ development of content knowledge and pedagogical approaches related to trigonometry.