Some films which have been classed as documentary are in fact in some ways works of fiction, with rehearsed scenes and dialogue, more especially some of the pioneering documentaries - and I think that in fact it is quite fair calling them documentaries.

The defining thing about a documentary is that it is primarily interested in giving viewers an understanding of some situation or people, rather than in telling a story, even if it uses a storyline as a way of achieving this.

Michael Moore's approach is polemic rather than reportage, and he is quite open about that. Some people make films which at least aspire to lay out the facts objectively, and leave any judgement about them to the viewers. Michael Moore doesn't do it that way.

But then, in truth, a very large proportion of people making documentaries and programmes that claim to be "onjectve" are in fact in the business of producing covert propaganda - and sometimes the people making them are so embedded in establishment ways of thinking that they probably don't even realise that.