In a novel you’ve got tons of space (60K – 100K words+) to develop character, build conflict, have those luscious high points followed by that great low where everything fails miserably, and then you have the time to build back up to the HEA that we romance writers love. You can manage all of this space through story structure, well plotted and thoroughly developed before you even begin writing. You can develop subplots and work out a romance along with a mystery, internal and external goals and so many other little pieces which will all fit together into the beautiful jigsaw puzzle of your novel.
But in a short story, everything’s got to happen so much faster! And not only that, but you’ve got to have that kick at the end – all good short stories have them. If you just have a happily ever after, well, it’s kinda boring, ordinary. A really good short story (and I’ve read a few to get the hang of it before I started writing one), has something at the end which makes you sit up or say “oh, no!” or some such wonderful concept. So your story structure, while following a simplified outline (set-up, rising action, climax, falling action, crisis, resolution), might, instead want to forego that nice resolution for a kicker that leaves your reader thinking or wondering.
The time span in a novel can be anywhere from a week to years to decades. In a short story, generally, they cover a much shorter time (although, naturally, I had to break that rule in mine – it spans the entirety of human existence, because when I break rules, I go all the way <g>).
POV and voice are even more important, I think, in a short story. You don’t spend a lot of time with your POV character, so your reader’s got to get comfortable with this person really quickly. A strong voice will help. In a novel, you can change POV, see the story from more than one pair of eyes. In a short story, you’ve got one set of eyes, any more than that and you’ll really confuse your reader. It’s too short for multiple points of view!
And finally, another big difference in writing a short story versus a novel is show and tell. So often, as a novelist, I’ve been told “show, don’t tell”. Tell only when what you’re writing about isn’t really important (someone getting up and getting dressed, we really don’t need to see every single little detail), but can be glossed over. Otherwise, everything needs to be shown, spelled out through dialogue, description and emotion. In a short story, however, you’re limited in space and word count. It’s got to be short. Showing requires a lot more words than telling does, so sometimes (quite often, in fact) in a short story, you’re going to do a lot more telling. The key here is to tell with emotion to keep your reader involved and invested while telling your story.
So, what am I missing here? What have you had problems with when going from one medium to the other? These are the few things that really stood out for me as I crafted my short story for an upcoming anthology (that you’re going to be hearing a lot more about the closer we get to publication day).