Elizabeth McCracken, in Writers Ask:

In graduate school, I wrote a short story that some said could have become a novel. I incorrectly believed my critics for a while. I wrote the first chapter of that story as a novel, then I realized I'd already written the version I meant to write. Novels that come out of successful short stories are frequently bad books. That's been my experiences. They were conceived as short stories: a short story is not just a shorter novel. You do character development differently. The characters are not conceived of as novel characters. I 've read too many bad novels published by good writers, based on really good short stories.

two things. one, i feel the same about short stories and flash. many comment on my flash, that they could see a longer story there. but flash is conceived differently, and making it longer, doesn't mean that it will evolve into a short story.

two, several years ago i read 'where the heart is' by billie letts, and the first chapter was great. the rest was mediocre. the author revealed in a note at the back of the book that she wrote the first chapter as a short story, and then an agent at a conference encouraged her to make it into a novel. there are probably many factors involved in this novel not being so great, but it certainly felt that she ran out of steam and was trying hard just to write something, after that first short story.

i had to google the title to remind me who the author was, and it seems there is a movie as well. so i googled the movie, and of course i remembered vaguely wanting to see it, as i like natalie portman.