I was elated when the NGSS Framework came out, in 2013, with a clarion call for a 3-D model of curriculum... We watched for 20 years as our K–12 colleagues tried every trick the gurus suggested to implement the 169 standards, assured that the hands-on would naturally, on its own, birth the minds-on and scientific literacy for all students. It didn’t. “Oops. Sorry about those decades of futile effort.”

A 3-D model of curriculum, teaching, and learning has a keystone proposition at its center. As we’re all science teachers, we can recognize it as a simple, quasi-chemical equation with roots in the 2-D content-process model.