But just because you can gather all this material doesn't mean it's useful or can help you tell a great story. It comes up in conversation all the time with new students.

They are overwhelmed with the material they have. Some have gathered hundreds of hours of footage of various kinds. But with more options to choose from, they've found it harder and harder to arrange it into a meaningful story.

So, what is a meaningful story?

In straightforward terms, it is a narrative that begins with a question in the audience's mind - how is this going to turn out? Your audience always asks themselves this question...

...it's surprising how often the documentary maker doesn't.

Because your audience will have asked themselves this question, they'll search for clues in the film they are watching.

What is your film trying to say? Why is it repeating itself? What is the point?

What my students say is the reason they are doing all their interviews and shooting all their sequences, is to search for the story. They know the idea means something to them; all they have to do is to keep searching, and the story will emerge.

Some of you have worked to find the story in your material for years. On the other hand, maybe your edit has gone on for months and months, and it's still not working. New shoots have been arranged, flights have been booked.

Others of you will have, tragically, just given up.

The answer to this problem is far more straightforward than you could imagine.

In conversation, a potential student said, "I guess if someone came to you and asked if you could make a film about sprockets, you could".

The answer is yes, and how long do you want it? 50 mins, 90 mins, a series?

The reason is that I immediately begin to think about what such a documentary could be... possible meaningful scenes and sequences spill out.

How were sprockets designed? When and why did they emerge? What problem were they solving?

I remember an ancient computer fished out of the Mediterranean with rusty copper sprockets. They are also part of those beautiful machines that modelled the movements of the planets - astrolabes. So computers, planetary movements and clocks are all based on the properties of a sprocket.

They may be a natural consequence of the invention of the wheel. Wheels slip. The sprockets on cogs add friction. Not just friction but friction at the extreme. They cannot slip.

Being in control of the world - seems like an interesting concept...

That's the practical physics of them.

And what do they say about the world itself? Why do they help us understand ourselves so well? Is there something about gearing that tells us something fundamental about the nature of matter?

And what about the conflict they might have created?

Anything new with such significance only exists with controversy. Are there people who felt that you couldn't - indeed shouldn't - mimic the design of God in a machine? How could something so simple predict the path of a planet?

On and on I could go.

I may want to argue that the sprocket is the precursor of AI. And the audience would ask me to prove it.

Is it an example of a technology that both solved and created huge problems?

All these potential ideas are built around a number of fundamental concepts about how a story works.

A key one is this..

... everyone in your audience looks at a problem from their point of view, their own way of looking at the world.

You have to give every single person an approach that satisfies them. No one in your audience should ever think, "What about this? What about that?". That means there are no more holes in your story.

You have to express the story so that the audience is clear about why you are telling the story this way. You are the author, after all.

• What is your genre - your style and tone?
• What thematic argument are you making?
• How about designing the climax, so that every issue you have raised is resolved?
• And then, you can think about the style of your documentary - the way you tell your story and make it engaging. Your perspective on this is unique, of course. It's what you grew up with and learned to love.

My point is - all this is pretty straightforward.

A system.

There's nothing to fear from a process as simple as this, because the results are hugely sophisticated - as complex as any story can be.

In the end your documentary will make sense.

It will be absolutely clear what your film is trying to say.

All the best - Nigel