Someone on Twitter asked me how I know if an idea is a short story idea or a novel idea. 140 characters isn't going to cut it for that answer. Novels for me either come out of the blue and are all WHOA CHECK ME OUT I AM SHINY AND HUGE AN
So, essentially, I'm at the point these days where I have more requests for material than time in the day, so I'm pretty much writing short stories either for Omikuji or because someone emailed me and gave me a deadline and a per word rate. So the process for me goes like this:
Have an idea. Maybe it's because the anthology is a nanotech werewolves in love anthology, so I have to come up with a nanotech werewolves in love story.
Write the story.
Get so wrapped up in the intricacies of nanotech being used to produce werewolves in an underfunded pound that my brain races ahead of itself, opening up to a whole world and I can see the shape of the novel behind the short story. Or in the case of something like Palimpsest, I wrote three lines and knew it was a novel. It's hard to say how I knew. I just did. It seemed like the idea of a sexually transmitted city could stretch that far.
Part of it for me is that I would much rather write novels than short stories, so I usually shake a short story to see if a novel will fall out. Sometimes it does, sometimes it doesn't. For example, The Radiant Car Thy Sparrows Drew is going to be a novel someday, because look at its bigness, its world, and how awesomely I could warp those characters given more space. Space-Hollywood, and quantum whales. Check out all its majesty. A Buyer's Guide to Maps of Antarctica is not going to swell up to a book, it's perfectly sized for a short story, in part because I don't go for long boring historical epics where like one fantastical thing happens. But also because it's more interesting only to see part of the whole, in that case.
So I guess it comes down to feeling. Any story can be big or small depending on how you tell it. If I leave Test Subject 7X, werewolf at large, pining after the mad scientist who made him and is even now succumbing to her own serum, then you have a story where I rely on the reader to imagine the conclusion--by ending it there I imply them getting together when Dr. Blackhall turns, and that's it. But if I made that chapter one, and then explored the good Doctor's painful conversion process and the slow turning of her affections as well as the world outside, the reasons for the serum development, the coming war with a species from Aldebaran that requires us to infuse the human race with power and strength, well, then it's becoming a novel, by god, because once you've got the world outside in, you've got two different plotlines going, and most short stories, especially of the ideally sellable length of 3-7k words, just don't have room for a lot of sub-plots.
But often I'm wrong. I fought the Orphan's Tales becoming a series for a long time. I thought it was going to be a longish short story.
Some ideas seem obviously novels to me. The Year of Red Snow, which I'm starting to work on this year, came whole parcel into my head while doing research on hyper-cold weather phenomena for another book. Given an Italian village who sees the red snow and endless winter of 1816 as the end of the world because they have no way of knowing a giant volcano blew its shit in Indonesia is not really a short story. Not the way I want to do it, to create a whole village, and entire history. Likewise, I had no desire to write a zombie novel , so I got it out of my system in about 3500 words in Days of Flaming Motorcycles.
This rambles a lot, and it is touchy feely. I feel this is big, and this is small, or big but best seen through a telescope. It's also an issue of desire. I want to write about crazy Italian narcopleptics and the Dormition of Mary forever and ever. I don't want to write about zombies that long. If I want to write a novel, I spin out the story. If I don't, I keep it thick and close. YOu have power over your tales--they can be whatever you like. Yes, sometimes they run away with themselves and get knocked up at a biker bar and all of the sudden you have a series on your hands. And that is awesome. But mostly, it's just: which do you want?
Does it have many subplots and supporting characters? Is it a big idea that needs space to honestly work out all its implications? Is it a vignette? A character study? Every novel has a fairly small story at its core: Lord Stableboy becomes King. Humans meet aliens. Unsuspecting malamute gets a bowl of Nanite Chow. It's the how that makes those stories huge and epic. The difference between a novel and short story, I think, is whether you fill in the edges or not. Where you shine the flashlight in the dark, and how much you illuminate there.