It's important to know that the IMDB relies on readers for accuracy of information and for rating the movies. So the number of stars is basically the current average opinion of people who bothered to provide a rating for a given movie. The classifications are also dependent on readers; some more obscure time-travel movies might easily get left out, possibly because the submitter wasn't aware of the classification feature or forgot to provide that information.<br /><br />Nevertheless, there are so many users that it's generally very useful. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em> -- The Tenth Doctor, "Blink"</font></p> </div>