After seeing a heavily censored version of this movie on television years ago, I was curious to see the unedited version. I was surprised that it was more believable and well acted than I remembered, but one thing really stood out. I think other reviewers have mentioned this also, namely, what exactly is the nature and motivation of the Chris Sarandon character? Has he raped other victims before? Is he completely psychotic or an "average" sociopath? How did he expect to get away with his attack on the younger sister? Is this character at all credible, or is it just a matter of more background being necessary? He seems almost simultaneously to be an uncomfortably believable character, and too crazy to actually be able to hold on to a teaching job that puts him in contact with young, vulnerable girls. This seems to to be the biggest complaint of viewers in general. It has nothing to do with his performance, which is terrifyingly convincing.The movie occupies an uneasy position between sheer exploitation and a half way serious treatment of the subject, without quite settling into either mode. Not the worst movie ever made, but not all that good, either.