Abstract: Many researchers and practitioners maintain that ACTFL's efforts to improve instructional practices and promote proficiency assessments tied to descriptors of what learners can do in real life have contributed significantly to second language teaching and testing. Similar endeavors in the area of research, however, are critically needed. Focusing on the oral proficiency interview (OPI), this article argues that ACTFL has a responsibility to its stakeholders to initiate a research program that generates a coherent combination of logical and empirical evidence to support its OPI interpretations and practices. The article highlights a number of high-priority areas—including delimiting purposes, examining interview discourse, documenting rater/interlocutor behavior, explicating the native speaker criterion, and investigating the OPI's impact on language pedagogy—that should be incorporated into the research agenda.