The real trick for me as a director is to make sure that people don't start pushing because the harder you push as a perform the less funny it becomes.

I remember when first, Stripes, and then Animal House came out - which I was really proud of, even though it was kind of loose and quite raucous - there were imitative movies that were not quite as good.

My first student film was Orientation, which was basically the set-up for Animal House. There are a couple of scenes that we later borrowed in some form.

There's been an amazing backlash for the last decade in America: political correctness. In many ways, I think that, while we've been remarkably violent in our media, there's been a real schizophrenia. In private, on the Internet, and on public-affairs shows or talk radio, we're way more explicit than we've ever been. But traditional Hollywood has been much more frightened than it ever was in the '70s about presenting things that could be perceived as politically incorrect.

I think if people want to see pure sex in the movie, they have the Internet and the extraordinary things are available.

Also watching a movie on DVD is different than watching it in the theater.

It's been about 15 years, and I've never really worked seriously in CGI and I thought that here was an opportunity to do the kinds of things that I was not able to do on Ghostbusters.