One of the key differences between science fiction and fantasy writers (and readers, I might say) is the ideal length of the manuscript. Fantasy requires a big canvas, whereas science fiction seems to shine best in shorter lengths. Most SF novels are a good deal shorter than fantasy novels, and it is in the short story length that science fiction really seems to sparkle. Fantasy is not well suited to the short story form, and there are far fewer fantasy short stories published -- so few, in fact, that I consider them a rarity, even in the magazines that claim to publish science fiction and fantasy stories.
Science fiction readers and writers denigrate fantasy as being big fat doorstopper books as if this is anathema to all that is good in writing. What they fail to realise is fantasy readers see this as a plus. I know myself I'd much rather read a novel, a long novel, than a collection of short stories -- I want to go on the long journey with the same bunch of characters. Short stories are hard work that way. I just get to know the characters and, pfft, the story is over. I'm not saying one form is superior to the other -- just that they are different, and different readers like different things.
So, I always find it interesting when people talk about building a career, and suggesting that the most important thing to start with is a series of short story publication credits. If I want to be a novelist, I want to be spending time thinking about my novel, building in depth, exploring plot twists. I can't do this if I'm writing short stories. That's not to say I don't write the occasional short story -- I do, but it's just not the form I'm most at home in. I do, however, think that the short story is an excellent training ground for would-be novelists. In a short story every word has to count. But every word should count in a novel too. There should be no flab. Long novels are not long because they are padded out, but because they have BIG plots.
I keep returning to an idea that Sherryl brought back from the States from the mouth of an American writer whose name I forget. He said that science fiction is a fiction of the brain, and fantasy is a fiction of the heart. Maybe that explains the difference too. Fiction of the brain -- ideas -- short story writers need lots of them. I can't say how much I admire prolific short story writers. My brain's not like that. But a fantasy of the heart needs space to develop the depth needed to really satisfy a reader.
I know Ian Irvine said, at the recent con, he would be astounded to find out that fantasy novelists needed a string of successful short story publications to be picked up. Most fantasy writers don't write them. Full stop. And I think that it's all very nice to build your profile this way, but will it really equate to more sales? None of the fantasy readers I know read short story collections, probably for the reasons I've outlined above. Still, it is nice to publish the occasional story -- just reminds you you are on the right track.