Attitude strength is defined as the extent to which an attitude is stable, resistant to change, impacts information processing, and guides behavior. Several concepts, such as accessibility, ambivalence, and importance relate to the broader concept of strength. For many years, both social psychology and political science ignored the differences across these various concepts, though in different ways. Social psychologists treated them as interchangeable, as indicators of the same latent concept. Political scientists treated them in isolation, focusing on one type of strength and ignoring the other, possibly relevant types. Recent research in both fields, however, challenges these approaches. Indicators of attitude strength are distinct concepts, and these differences are important empirically and theoretically. In this essay, we review the developments in both disciplines and make suggestions for how scholars should use and operationalize these concepts.