To support teachers in implementing ambitious reform efforts, professional developers and teacher educators need to know more about teachers' thinking about argumentation. Specifically, there is a need to understand more about teachers' views and evaluations of "students'" mathematical arguments as they play out "in practice."…

I present my perspective on the design process in this article, arguing for a focus on student learning and "slow design" that stems from knowledge of mathematics and their support system in the learning process. I have a question about the design process academization and task design research direction. Numerous examples from my work at…