... it develops in most classrooms, students’ talk frequently expresses multiple intentions or voices (see Ballenger, 1997; Bakhtin, 1984; Warren and Rosebery, 1996; Wertsch, 1991). In their narratives and arguments, students express both scientific and social intentions: scientific in that the ... ; social in that they also talk about themselves as certain types of people (e.g., virtuous, honest, trustworthy). If the responses of other students and the teacher to these multivoiced narratives are always keyed to the scientific point, it helps to shape the meaning that is taken from them and ... them back to the context of the unfolding scientific argument (Ballenger, 1997). In standard science lessons, the scientific point in the talk of many students, particularly those whose discourse is not mainstream, is often missed, and the ... intention is often devalued (Lemke, 1990; Michaels and Bruce, 1989; Wertsch, 1991; see Chapter 7)....