There is an increasing complexity as you move across the levels. In Emerging, students ask and answer yes/no questions with simple phrases. In Expanding, students ask relevant questions, affirm others, add relevant information, and paraphrase key ideas. In addition to the skills of a student who is expanding his or her skills, "Bridging" students build on responses, and provide useful feedback.
Notice that the descriptors for exchanging information/ideas and supporting opinion and persuading others correspond with standards SL.8.1, 4, 6; L.8.3, 6; WHST.8.1.