If Andrew Bujalski never heard the word 'mumblecore' again, he'd be quite happy. 'I'm tired of hearing about it,' he explains from Austin, Texas, days after his latest film, Beeswax, had its world premiere in Berlin. 'I'm tired of the reduction inherent in it. It's designed to take a lot of film-makers and dismiss them all in one fell swoop. I understand why it's useful for critics and writers, but it doesn't mean much or do much for me.'

Bujalski does not deny a shared spirit between the film-makers, who include Joe Swanberg, the Duplass brothers and Lynn Shelton. All tell stories about interactions between young people, filmed on handheld cameras and often with non-professional actors.

Bujalski even acted in Swanberg's Hannah Takes The Stairs in 2007. 'The films are good and I like the film-makers so I don't mind being lumped in with them,' he says. 'But it's not just the spirit of the film-making (critics) are referring to when they use this term.'

Bujalski certainly has a unique storytelling style. His three films - Funny Ha Ha (2002), Mutual Appreciation (2005) and now Beeswax - are all achingly authentic, partly because they feature actors with whom Bujalski has a long personal history, although his work is scripted and not over-improvised.

'I would take a very different approach if there were movie stars in the cast,' he laughs. 'That's the whole trick we're trying to pull - that it feels organic. And if someone comes out of the movie and says we were just making it up as we went along, part of me likes to take that as a compliment.' He laughs. 'Part of me has a bruised ego, of course.'

One Bujalski-ism that is starting to divide audiences is his method of ending the film in full flight, on a cliffhanger as it were.

'I just don't identify that well with conventional closure,' he says. 'It's more interesting to me not to wrap things up neatly. I understand people will walk out a little baffled, feeling like they've just been smacked, and I apologise for that effect. But my hope is that a day or a week or a month later, if they remember it at all, it will make the rest of the film resonate for them. To me, leaving the questions open informs the rest of the story.'

He says Berlin audiences responded to the film but jokes that subtitlers find his dialogue-heavy films quite labour-intensive. 'Everyone who has subtitled one of my films mentioned that it's a lot of work. There's obviously a lot of talking and subtlety happening at the level of the dialogue.'

Bujalski's interests, he says, are broad and he is now feeling the itch 'to do something unlike I've ever done before'.

'I don't know what the future holds. My best guess is that my next film, should I be lucky enough to make one, is either 10 times as much money or one 10th as much as the last one.'