Is It Lying?

Question of the day: Is it wrong to mislead students in an effort to inspire them to achieve?

Scenario in question: I recently had my U.S. History students watch a video about the Civil War and then write an essay analyzing it as a tool to teach one about the Civil War. In other words, they could watch something like Glory (that was one of the movie choices), research its accuracy, then explain whether the film would be effective in teaching about the period. Right before passing back the essays, I showed students a sample essay on the overhead projector and critiqued it as I read it. I assured students that the author had given me permission to read it, but did not say who wrote it. I am careful not to say "The student who wrote this" but rather say "The person who wrote this" or "The author of this essay has given me permission to use it."

The essay was very well written, with only a few minor mistakes. It was a great model to show students what constitutes good writing. This is the kind of thing many of them need to see, as they tend to be lacking in the area of writing. The hope is that they will see good writing, note the kinds of things their current writing lacks, and work on making changes to improve. So what's the catch? I wrote the essay. Yup, I concocted it two years ago as a model of the types of things that should be done in a good piece of writing. I neglect to let my students know it was not written by one of them. Is this wrong? Is this a deception that is going over the edge? I hope not. I will not lie to students if they ask me who wrote it, or insist that it was really a student who wrote it. If they press for details, or are suspicious about its authenticity, I just tell them I will not give away any more information on the author, except to say that I have their permission to use it (I can give myself permission after all, can't I?).

So what say you? Is this kind of leaving out all the details about authorship acceptable, or sinful? :-)