[Jack B Nimble]

One of the best approaches I have seen to this question comes from an old Professor of mine (sadly, his name is lost to the cobwebs of my memory). When he assigned the first term paper for the class, one of the students asked how long the paper should be. His response: "Do you want me to read it, or weigh it? Make it as long as it needs to be to cover the topic."

You can tell a great story in just a few pages such as Bradbury's "The Pedestrian," still one of my all-time favorite stories. The Lord of the Rings is also a great story, but I would not be surprised if the Cliff Notes version is longer than a novella. As several people have already said... it depends on the story.

Jack