pg 258 "In collaborative discussions, the teacher's comments direct students not only to understand what others are saying, but also to respond to, extend, or connect to those ideas. For example, the teacher can ask, "Does anyone want to build on what sally just said?"...However, the teacher can encourage students to work directly with one another's ideas and can take steps to foster such interactions."
pg 258-9 "To get students to listen to, comprehend, and extend other's ideas, teachers must ask them to do this consistently and not only in a whole-class format. For example, during a group work, the teacher can actively support collaborative discussions by engagin all students at the table in the conversation...the teacher responded only to "group questions" or called on specific students to ask the question to make sure that everyone was in agreement with the necessity for a question and what the topic should be.