Theories of social interaction focus on attributes of persons, situati
onal expression of these attributes, and relation of personal attribut
es to those of others in groups. Task groups are the main topic of int
erest in these studies. This article briefly reviews core ideas of one
theory of interaction. This theory emphasizes the relational explanat
ion of organizing interaction. Developments within the theory bared on
research that is both supportive of it and challenging to it are disc
ussed. The article concludes with a brief overview of other articles i
n this special issue.