Although most tasks that STEM professionals engage in--like identifying problems, making models, and testing those models--involve inquiry, many STEM classes still rely on direct instruction. Stephan argues that even as new resources for active learning are being developed for STEM instruction, many teachers aren't using these resources and tasks connected to them in ways that let learners engage in true inquiry. She offers a framework for helping teachers plan inquiry-based STEM lessons and gives suggestions for how to launch an inquiry-based lesson in a way that leaves the work of unpacking the problem and exploring ways to solve it (the cognitive demand) to students. She provides two examples of a teacher's introduction to the same task involving the relationship between the diameter of a circle and its circumference--One is so prescriptive that students lose the chance for true inquiry. The other invites students to explore the problem and come up with their own methods for solving it.