Here is a discussion at UV Law. In the main article, the author wrote, "Consider this. If you’re in class, given an open book exam with a time limit, and you copy something from the textbook, is that plagiarism? Most of us would say no, but I know some professors who would say yes." Well, I guess jerks at Duke would say yes. In the discussion part, a commentator argued, "Copying from a textbook is what you’re practically expected to do in an open book exam! Now, granted, if you do that and nothing more, you won’t get a very good grade (unless it’s a VERY poorly written test), but plagiarism? Are you nuts?! "

source: http://www.cavalierdaily.com/2009/11/12/simply-mistaken-2/