of our design principles. Therefore, all six professional learning tasks included aspects of
students’ mathematical work or activity that had the potential to generate discussions about
mathematics content. However, from the six task sequences, only four generated discussion
around SMK, and these four were all designed to address the more advanced levels of
the EPLT. At these levels, teachers were more likely to have less sophisticated understandings
of the content and therefore perhaps a higher need for conversations about SMK.
Thus, similar to Mojica (2010) and Wilson (2009), participants in the professional
development learned both PCK and SMK. However, they only seemed to change their
discussions from PCK to SMK in situations for which the mathematics was perhaps
difficult for them; for tasks around lower levels of the trajectory, teachers did not take up
the embedded mathematical SMK issues and attended only to pedagogical issues.