This paper discusses the conceptualization of interpersonal power and offers a relational definition and measure of power. A distinction is made between "power attempts" (domineering message behavior) and "power" (transactional patterns of dominance). To test this distinction, 45 husband/wife dyads were randomly sampled from a midwestern metropolitan area, and two types of data were collected: first, self-report information concerning the marital relationship was obtained from each husband and wife separately; second, interaction data were obtained by tape-recording, transcribing, and coding each couple's discussions of four family-related topics. The findings support the views that domineeringness and dominance are separate control variables and that different dyadic patterns of satisfaction and interaction style are associated with these two dimensions. (RL)