Both theoretical frameworks, those of mathematical knowledge for teaching
(MKT, Ball and colleagues) and the Knowledge Quartet (KQ, Rowland and colleagues) represent developments of Shulman’s frame. Could they perhaps share something else in common which might help us explore the complementary of the approaches in the chapters by Turner and Rowland, and by Corcoran and Pepperell on the one hand, and Tirosh, Tsamir and Levenson on the other? And, what of the differences?