I recently stumbled upon micro-credentials, an interesting new approach to professional development. One thing that has stood out to me before about professional development is the lack of follow-up; to have, say, two days of workshops on holding reading conferences and using mentor texts, but never returning to that idea again. How can a school ensure that teachers get the most out of professional development? That money spent on PD is worth the opportunity cost? That teacher time spent listening to presentations improves student learning more than that same time being spent on designing instruction and reviewing assessments?