I believe that improvisation is really just a directorial tool. It's a writing tool. It's not so much that the actors get to say whatever they want, whatever pops into their head. It's an opportunity to write the last draft of the screenplay as you're working on it.

Everybody says how hard comedy is, but, when it comes time to honor things, whether it's on a weekly critical basis or whether it's award time, at that time of the year, comedy is the poor, dumb child of dramatic work.

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 don't think there will be another Ghostbusters. I think we're all too old to do it. I think we've done it a couple times and there is not that much to get out of it, to do that would be fresh in it.

I've always been a fan of science fiction films, and I've never been able to put my particular spin on it.

I believe that improvisation is really just a directorial tool. It's a writing tool. It's not so much that the actors get to say whatever they want, whatever pops into their head. It's an opportunity to write the last draft of the screenplay as you're working on it.

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.