Recent scholarship in political science has expanded our understanding of how personality affects political behaviors, attitudes, and learning. However, a major obstacle to expanding this research agenda is that many established personality inventories contain far too many questions for inclusion on surveys. In response, researchers typically select a subset of items to administer, a practice that can dramatically lower measurement precision and accuracy. In this paper, we outline an alternative method – adaptive personality inventories (APIs) – for including large personality batteries on surveys while minimizing the number of questions each respondent must answer.