Abstract
Our fundamental scientific task is to convert observations of particular persons behaving in particular ways in particular situations into assertions that certain kinds of persons will behave in certain kinds of ways in certain kinds of situations, that is, to construct triple typologies or equivalence classes—of persons, of behaviors, and of situations—and to fashion theories of personality that relate these equivalence classes to one another. It is argued that the different approaches to the study of personality are distinguished from one another not by whether they are idiographic or nomothetic but by the strategies they employ for constructing—or ignoring—each of these three types of equivalence classes. The likely attributes of a successful interactional theory of personality—one that would embrace the entire triple typology—are proposed and discussed.