We spent numerous classes going over the outcome of writing a persuasion letter. I had my students write (“word process”) several persuasion letters for homework. When they came into the class with their homework, I gave them a model/exemplar written answer for each of the homework letters. I asked them to compare their own letters with the model letters. They wrote in the margin of their letters what they now would do to improve their letters. I gave them the option of redoing their letters before they handed them in.
Their students offered great self-reflections. “I realize by their listing the items, they are easier to read.” “They started off by really getting their attention. I just made a general statement.” “The letter made me really want to buy the product. They showed how my life would be so much safer with it. I had listed some advantages but did not emphasize the emotional appeal of these advantages.”
How do give your students feedback on their homework through models?
Education with Technology Harry G. Tuttle 
Hello,
That is an awesome idea! I would love to see that extended into a math classroom where students bring in work and compare it to similar examples and look for differences. A teacher could also give students an example of a problem that was done incorrectly and ask them to find the error(s).
John,
Some math teachers may do it when they go over homework at the beginning of class. If they show how to solve a complex problem and ask students to compare the model with their own work, to note any differences, and to indicate whether the differences are are due to alternative successful thinking or on the other side, a misunderstanding or a miscalculation. When students become active assessor of their own work, they learn much more in class.
Harry