Comments on the article by Miller and Rose (September 2009). As Miller and Rose opened "the black box of treatment to examine linkages between processes of delivery and client outcomes" (p. 529) in motivational interviewing (MI), it is important that their model include factors from the social context that may explain conditions that enhance or diminish MI interventions. Aspects of the social context may serve as mediators or moderators of the relational (MI spirit) and technical (change talk) components in MI theory. In this comment, the author suggests the addition of social influence to their theoretical model. The author suggests that existing research on the role of significant others argues that the conceptual model should include a box for Social Influence as a hypothesized process variable that relates to "Client Preparatory Change Talk and Diminished Resistance" and "Commitment to Behavior Change" (see Figure 1, p. 530). In addition, a second new box, labeled Significant Other Training in MI, should be added in direct relationship to the new Social Influence variable. Further research is needed to explore these variables and their specific functions within the model. These additions to the theoretical model affirm the active components of MI and potentially extend the effects through positive social influence.