Professional learning approaches and programs do not drop from the sky fully formed. Yet often those who are expected to engage in them — teachers and other staff — have little information about how these approaches developed and the type of expertise that shaped them. What goes into creating them? What kind of knowledge do the developers of professional learning need — and do they currently have it? A recent study by Northwestern University researchers Richard Paquin Morel and Cynthia Coburn examined one potentially important element: the system of support and resources to which professional learning developers have access. The researchers studied both “system” providers (such as schools, districts, and education policymakers) and “nonsystem” providers (such as textbook publishers, nonprofits, and commercial enterprises). Both groups