The education research community is trying to figure out how to foster and assess responsive teaching, which in turn requires us to conceptualize what counts as progress toward greater responsiveness. The analysis empirically establishes that teacher's attention can shift not only between the substance of student thinking and other things, but also between multiple foci within the substance of student thinking; and these foci sometimes cohere into coarser-grained coherences of attention and responsiveness. These results are to challenge notions of expertise in responsive teaching and associated assessment schemes that equate levels of responsiveness with particular foci of attention or types of response, without analyzing the teacher's intent or the broader flow and context of the classroom discourse. Researchers studying teacher responsiveness rarely distinguish among the various facets of disciplinary substance within student thinking. Attention and responsiveness to the substance of student thinking is instead defined in opposition to other foci of attention, usually canonical correctness.