Social-scientific theory usually represents an attempt to describe or explain social phenomena and, sometimes, to criticize them. However, a theory can be transformative in the sense that in using and testing it, researchers may help practitioners transform and improve their social conditions, institutions or organisations. This idea is illustrated by a research-and-development effort to help conference organisers develop meeting formats that create more learning among delegates than is accomplished by the conventional, lecture-based format. This effort was based on a (transformative) theory of conferences as forums for learning and "human co-flourishing." Seventeen learning techniques were derived from the theory and were tested as hypotheses: When implemented in 30 live experiments, did they contribute to learning, as specified by the theory? Properties of transformative theory that distinguish it from the good intentions harboured by all change agents include theoretical grounding, a coherent ontology, testable hypotheses, systematic evaluation, external validity and theory-action consistency.