certain lengths and color to measure the length of a student’s desk. Then, she divided the class into small groups and asked them to measure their desks using rods of different lengths. After she placed samples of the (magnetized) rods on the chalkboard, the following exchanges between teacher and students transpired: Example #7 Initiation Responses Feedback T: So, what I’m interested in hearing now is how you figured out how many blue, red, and white rods it took to stretch across the table. And I’m also interested in hearing how many different ways there are to think about that. So, Craig, how many blue rods does it take to stretch across the table and how did you figure that? C: Six and two thirds T: And how did you figure that out? C: Because, um there is 3 light greens that fit into the blue and then you go “3, 3 greens times 6” that would 18 and that won’t be a full rod so take off 2. So you put down 2 and take out one green. That would be 2/3, that would be 6/23 T: And Nathan, how many blue rods do you think stretch across the N: About 6 T: And explain to me how you got that answer N: We took the blues and then took the light greens and compared how many would stretch across and worked our way down and got up to 20 green. And we just stuck these on top
pumpkins open up and they have- and they drop seeds.” On another occasion in the lesson, the teacher asked Hakim to explain his reasoning: “Can you explain how you think that?” Hakim obliges: “Because there’s seeds inside a pumpkin, because there’s seeds inside a pumpkin and sometimes some of the pumpkins splat open and they get planted by theirselves.” When she explicitly invited other students to assess Hakim’s assertion that pumpkins are like spiders, the teacher received a range of explanations, all of which began with a “because clause:” Hakim: “Because sometimes some pumpkins open up and they have- and they drop seeds. And sometimes farmers collect them and then they put ‘em in the ground. “ “um ‘cuz they plant more- um because they get planted all over again.” Ayanna: “and it’s kinda’ like the same because um the um rotten pumpkins- ‘cuz of the rotten pumpkins and the um spiders, they’re getting old and that’s how they die.” On another occasion, when the teacher asked “is there a pumpkin inside a seed,” one student (Nick) answered “no,” while another (Suzi) answered “yes.” The teacher then encouraged them to provide evidence of their reasoning. From Susi, she received this response “‘Cuz it’s like a sprout of a pumpkin.” Throughout this discussion, the teacher seldom evaluated the quality of students’ answers or sanctioned violations of turn-allocation procedures. She did reformulate students’ answers often, however. For example, Hakim modified his original position and now asserted “The seed is almost like an egg.” Bruno recapitulated this position: “The seed is kinda’ like an egg because an egg ‘cuz like something’s inside a egg.” The teacher reformulated these observations as “a seed is like an egg.”
Even though this lesson continues past the point at which the transcription stops, this excerpt provides sufficient detail to illustrate the ways in which a teacher can invite students to reason with evidence. The teacher introduced the norms for classroom discussion throughout the school year such as insisting that students listen carefully to one another, give each other time to think, and direct a comment at the author of a previous comment. She reinforced them within this lesson: (“lets make sure everyone’s looking at Mathias, to show we are listening to him;” “talk to Mathias about how you feel about what he said;” “talk to him and tell him why you disagree with him”). Here are the discourse moves appearing in this transcript followed by quotes from the teacher: Discourse goal—Helping students use evidence of reasoning Specific moves: “Do you want to talk to the group about the conclusion that you came up with?” “Javon, what do you think would happen if I put an object this big in a cup of water?” “Alicia, you want to share with the group some of your thoughts?” “Aisha, you want to add something?” Discourse Goal--Helping students deepen reasoning by challenging or providing a counter example Specific move: “Does anyone want to respond to that?” Discourse Goal—Helping students listen carefully to one another Specific moves: