In Robert Lee Mahon's article, "Try the Guillotine," Mahon argues that it is imperative for an instructor to know their personal attitude and definition of plagiarism before explaining the policy to students. Mahon advises that in order to handle plagiarism in the classroom, the instructor must, "ignore the ethical ins and outs, and forego any sentimentalism about your opponents and the problems and temptations they face" (272).
Mahon advises that instructors have high expectations for their students to prevent cheating. In order to do that, Mahon advises a strict "zero tolerance" policy for plagiarism that is stated on the first day of class. "Plagiarism is turning in stuff that other people wroter...plagiarism is therefore a capital offense in a writing class...anyone I catch plagiarizing gets an automatic F for the course" (272). If Mahon believes that someone has plagiarized, he flunks the paper. Though he leaves it up to the student whether or not they want to contest the claim, he believes that the "guilty until innocent" approach works.
In order to pull off the guilty until innocent approach, it is crucial for the instructor to see the work at several stages of development. Familiarity with work removes the the occassion of discretion in a student's writing, and allows the instructor to become more comfortable with the students style of writing. As Mahon states, "the very students most tempted to cheat are the ones who have been producing half baked work" (273). In a sense, this is a way to monitor progress, and try to catch the perpetrators in action.