Editing Stories Using Review/Comment on Word

In the past I had the students print their articles/stories and then I would edit with them using the paper copy.  It was a struggle to get them to make the changes on the computer.  I don't know why.  Some would do it.  Others would fix one thing and tell me they were done.  We wasted a lot of paper, ink and time.

Finally decided to try the review section of word and add comments to the students' documents.  The biggest problem was students deleting the comments.  I'm looking for suggestions on how to stop them from doing that.  Otherwise, I think this is the way to go from now one when editing the stories.