Students can take notes on, and include, opposing views in their essays. The groups could note assumptions, pinpoint contradictions, and look for strengths and weaknesses in the arguments given. Each group could recap the main points of their discussion to the entire class. Encourage the groups to find some points of agreement. You may want to have students argue each other's positions.
Students can then evaluate each other's presentations of their arguments.
Have students rewrite their papers. Another lesson could be used to develop students' ability to clarify issues and concepts, again using the model arguments previously mentioned. The teacher can have students identify the key terms in the model arguments. Ask students to describe examples to which the key words or phrases in the model arguments would properly apply. Then ask for examples of their opposites.