I received this from a professor the other day, it articulated something I have been thinking about for years:

A situation is not a story.  A story is a beginning middle and end about someone who wants something and goes after getting it.  They can’t just want anything, though, they have to want something in the long term, something that will require them to adopt a series of short term goals that, if attained, will get them their long term goal.  The character can have a series of long term goals over the course of the story, as in The Wrestler (first he wants to become successful again at wrestling; then, after his heart goes bad and he can’t wrestle anymore, he wants to try to live the normal life he’s always been avoiding by reconciling with his daughter and trying to get a girlfriend; then when he fails at that he wants to die, so he goes back to the ring), but the character needs long term goals that will engender short term goals.

So, when you have an idea for a film, short or feature, ask yourself;

Is it a story or a situation?

Some examples:

A man gets hit by a bus – Situation

A man wants to kill the driver of the bus who hit him – Story

A college student gets a new, obnoxious roommate. – Situation

A college student desperately wants to drive his new, obnoxious roommate out of their dorm. – Story

A story has a goal, which implies conflict, i.e. obstacles, antagonists etc. A story with a goal also implies a beginning, middle and end. A situation can continue on indefinitely. Life is composed of many situations, most of which are inadequate (without goals) for depiction in film.  Interestingly, some short films, including Oscar nominee Manon Sur Le Bitume succeed despite their basis in situations.

As John August once wrote: life is characters without a plot.

As David Mamet said at the Arrow last night; it is the role of the screenwriter to provide the plot.