Abstract Professional learning about an innovative teaching method is a demonstrated way to improve teacher practices, and ultimately impact student learning. One way to scale up professional learning is a facilitator development model, in which professional learning and development (PLD) designers prepare facilitators to understand the innovation and they in turn, teach teachers. To understand the effectiveness of this model, identifying how facilitators implement the model with teachers is critical. As such, the Power of Data (POD) team scaled-up effective PLD by providing Facilitation Academies to teach others to facilitate POD Teacher Workshops (TWs). The expectation was that changes based on local contexts would occur; thus, we focused on Integrity of Implementation (IOI) rather than fidelity of implementation. A measurement approach for IOI was created to understand how facilitators (n=13) delivered TWs and how they retained or modified the program principles. Examples from this project illustrate how a robust IOI measurement approach based on a variety of data sources can inform the design of PLD experiences, enable understanding of teacher PLD experiences, and allow researchers to determine whether the scaled-up model is effective. Citation Whitworth, B.A., Rubino-Hare, L. & Bloom, N.E. (2022). Scaling professional development: Integrity of implementation as a measurement approach. Science Educator, 28(2), 75-85.