A professional development session can look successful because the strongest, most experienced people in the room know what to do with it. But that can hide a design problem. If the people who already had the background knowledge, confidence, vocabulary, or prior training were the only ones able to translate the session into practice... what exactly did the training accomplish? Sometimes the people who appear to have “learned fastest” were actually filling in gaps from years of previous experience. That is not a criticism of them. It is a question about the learning design. Did the training make the practice accessible? Or did it work because some people already knew enough to compensate for what was missing? I think that distinction matters whenever we evaluate professional learning by looking only at who succeeded afterward.