I've recently discovered that the Filmmaker Magazine blog features a regular column called The Microbudget Conversation. I just read this piece written back in August by guest writer Nicole Elmer about the limitations of scripting micro-budget films and the avenues opened up by using improvisation:
It was a creative choice as much as a budgeting choice. Because of the specificity involved, a script would have required the costly fabrication I mentioned earlier. Instead, the writer created a very basic outline that was broken down into scenes. Locations were replaceable and everything could be moved as needed, as long as the general symbol of the moment was still expressed. A script would have also forced us to shove dialogue in the actors’ mouths. Instead, we gave the actors their goals, they developed their characters WITH the writer, and we gave them responsibility for their dialogue, a creative choice normally made by a screenwriter.
Of course, many filmmakers from Mike Leigh to Rob Nilsson to Terrence Malick work by balancing structure and improvisation. Elmer says that it was a creative and budgetary choice, but I know if one were to ask any of the filmmakers listed above, they would reply that their choice was purely aesthetic. Nilsson even has a brief manifesto on his website ("Create a poetic cinema based not on writing but on observing. Mistrust your ideas and trust your experiences. Discover, don’t prescribe"). Personally, I think films made in such a fashion are, at their best, some of the most profound in cinema. They show life happening and us happening back, to paraphrase Nilsson's manifesto.
It all goes back to what I said about meaning in my last post. And this is not to say that I reject scriptwriting out of hand, of course. All of this is too much for a brief post, and I've been planning an essay-length post on it all sometime in the near future. And also, if that Nilsson manifesto is too brief, there's always The Path of the Artist by Ray Carney.