The relationship between John and Carol is interrupted.  This is literally seen in the exposition of the drama with the phone interruptions.  Their relationship is interrupted by the external force of the phone. Its constant ringing and the interruption of legitimate discourse between John and Carol helps to establish the basis of their relationship.  

Yet, in another sense, John's and Carol's relationship is interrupted by external forces appropriated within their own identities.  The perceived gulf between faculty and student serves to "interrupt" their relationship.  John is unable to transcend this chasm in trying to legitimately reach out and connect his instruction to her understanding.  His concerns do not lie in her comprehension of material, as much as they do with tenure and the cultural capital attached to it. At the same time, Carol is unable to overcome the internal conditions within her own psyche that reaffirms her own failure.  The entire premise of her being in his office is because she "doesn't get" the material.  In each of these conditions, their relationship is interrupted by external realities that they have appropriated within their own senses of self.  Their relationship is further interrupted by the demands of John's outside world in the form of the house closing and his role as a husband.  These elements contribute to a relationship of perpetual interruption.  Even in the earliest stages of their relationship, there is nothing seamless and smooth in their relationship. Everything between John and Carol is fraught with interruption and distortion.

Such a condition magnifies as the drama progresses.  The inevitable draw of both parties seeking power helps to interrupt their relationship even further. As the accusations begin to take form and the sides are drawn, the relationship between John and Carol becomes further interrupted by the social constructions of power that are outside of them and within their own identities.  Their relationship becomes further fragmented because of these interruptions.  The desire for power is real and in both of them, the desire to appropriate reality or construct truth in accordance to it is critical.  This is elemental in John's and Carol's relationship.  It is an interrupted entity, one in which the desire for power and control overcomes any chance of resuming communication. Interruptions that exist both internally and externally define their relationship. Mamet's presentation reminds us that some relationships are incapable of overcoming interruptions and distortions, and in this failure, the basis for perpetual conflict is evident.  This state of endless conflict is what defines the relationship that John and Carol share.