This chapter is concerned with three systems, three modes of organization of the elements of action; these elements are organized as social systems, as personalities, and as cultural systems. The box in the center shows how social systems and personalities interpenetrate one another whether they are subjects or objects: a role is the segment of a personality's actions which goes into the constitution of any particular group. With the transition to the analysis of systems of action personalities and social systems the descriptive structural analysis with which we are particularly concerned begins to shade into dynamic analysis. The chapter is devoted to the highly important, derived, classificatory system, the pattern-variable scheme. The distinction between the modalities of qualities and performances as foci for action orientation has already been discussed and does not need to be elaborated upon here, except to note that it presents an authentic selection alternative involved in all systems of interaction.