How can we empirically identify and measure policy learning? Through a problematized review, we develop a novel perspective to identifying, explaining, and addressing interconnected ontological, theoretical-contextual, and consequently, methodological challenges in the measurement of policy learning. We de-compose measurement as a three-fold endeavor, concerning: conceptual foundations, the design of measurement instruments, and their deployment in empirical research. Then, we synthesize exemplars of good practice across these three stages and offer a set of recommendations for the refinement of policy learning measurement, while maintaining theoretical and methodological pluralism.