It is often said that students who perform well in school are those that understand the rules of the game. In other words, students need to understand not only the content related to an activity, but also the teacher expectations for how to participate in that activity and how the activity is typically structured (Doyle, 1979; Mehan, 1980). Lemke (1990) provides an example of a predominant activity structure, which can be characterized as following the sequence "Teacher Question-Student Answer-Teacher Evaluation" or as Mehan’s (1979) more general sequence of “Initiation by teacher-Reply by student-Evaluation by teacher” (I-R-E). Recently, an investigation of United States mathematics and science classrooms by the Third International Mathematics and Science Study (TIMSS) has confirmed this earlier research indicating that there are clear patterns of classroom activity structures. TIMSS found that most science instruction involves activities that are short in duration and that focus on transmission of information (Schmidt et. al., 1997).