'I have made films in a very different style. This is just a particular way of telling a story. Documentary formats should be allowed to change; the trouble is if you break an established way of telling a story, some people prove resistant to it.
'The Margaret Thatcher film was about a very public figure. I wanted to entertain people who don't have a specialised knowledge about Thatcher or might not be avid newpaper readers, and who probably wouldn't watch a Dispatches or a Panorama.
'It all comes down to giving the viewer enough information to follow the story. Obviously if, for example, you've got a lot of phone calls and you can't film the person at the other end of the call, you're stuck with filming yourself.
'I think the more personal people make their films, the more interesting they are. Anything that involves an audience in something beyond telling the objective truth - which is a load of bollocks anyway - is very interesting.
'The whole old BBC way with an apparently impartial voice telling the so-called objective truth should have been completely discredited. There is no such thing as objective truth; what there is is subjective truth and the storyteller, and I think the audience needs to know a bit about the story- teller to be able to decide whether they believe the story.
'I spent years making films in a more traditional style. But very often the most interesting aspects of your subjects you can't film because they're inaccessible by the traditional means. When you meet someone for the first time, those first few minutes are much more significant than when you finally sit down on the couch and start to interview them - you see a personal side. And then again when you pack the cameras up to leave. It was a question of evolving a style and structure that enables one to do that. Documentaries aren't so much about giving factual information as about giving a feel of a person or a situation.'