L'allievo

I read the novella in high school, and I found it scary, disturbing, and a real grabber - I couldn't put it down until I was done.

As for the movie version, I'm sorry to say it doesn't work. While there have been much worse Stephen King adaptations, this is still pretty weak. Someone else here said it's been sugarcoated, and I agree. It's been watered down so much, that character's actions that were easy to understand in the book become "Whaa - why did he do that?" here. The ending is the worst part - though I can understand why they may not have been able to recreate the novella's original ending onscreen, couldn't they have thought of a new ending that was better than the one they used here?

The acting is good, one of the few things that works here.

In short: if you have read the novella, do NOT watch this movie - you'll be horrified in a way the filmmakers didn't intend. The positive comments here seem to come from people who haven't read the novella. I still wouldn't recommend this movie even for non-readers, but if you must watch this movie, I strongly urge you to read the novella after you've seen the movie. It'll really open your eyes (in more ways than one), and you'll see how much better the movie could have been.