Dialogue is a tricky thing, even in flat fiction. It needs to sound plausible, but not too realistic. (It turns out real dialogue is boring to read.) You need to give characters a unique voice, but not to the extent of being distracting, confusing, or inadvertently offensive. And you need to get to the point; if dialogue in your short story, novel, or film doesn't do anything to advance plot, reveal character, or support your theme, odds are good you don't need it.
These are the structural concerns with dialogue -- the things that will affect the content of your story. There are also technical concerns: where to put in tags like "he said," how to punctuate, how to break up cadence, whether to phonetically convey accents (hint: no, don't).
For a transmedia project, the structural concerns are much the same, but you have a whole new and different vista of technical problems to deal with.
Transmedia is All Dialogue
Dialogue is incredibly important in transmedia. Think about the parts of a project that wind up as written words: blog posts, tweets, photo captions, emails, status updates, letters or postcards. Then there are the spoken words in phone calls, voice mail messages, video clips, and so on. All of it is dialogue.
OK, technically a lot of it is monologue, but bear with me while I explain. All of these things are dialogue in the sense of "words that the character has directly chosen." Written words shouldn't be in your writing style; they should be in the style of the character who has, in your story world, written them.
Ideally, every scrap of it will reveal character. There's no such thing as throwaway text. Not an autoresponder, not the title of a photo on Flickr, nothing. Every single word should be scrutinized to make sure that the tone is in character, just as much as the content itself is.
And, as Nina Bargiel commented in a previous post, you have to make the writing itself distinct. Not just where it appears, but how. Does a character say "dude" all the time? Drop subjects? Swear a lot or never? Capitalize Random Words? Overuse emoticons and punctuation!?!? :D :D ..what kind of emoticons? :-) B`} ^_^ Do they use l33t sp34k or txt abbrvtns? Do they insert action descriptors *types furiously* to show you what they're doing or thinking?
You get the picture. In transmedia, knowing this stuff about your characters is necessary. Waffling between these, unless you do it for a specific effect -- like dropping emoticons when a character gets serious -- is going to muddle up your characterization. That hurts your story.
Craftsmanship aside, let's look at the technical aspect of conveying dialogue. For our purposes, I'll divide it into two kinds: Dialogue between two or more characters, and dialogue between a character and the audience.
Dialogue between two or more characters can be tricky. Assuming you don't have a web series, graphic novel, or other single-media outlet for your multiple-character interactions, then you need to make some choices. First, was it a private or a public conversation? And second, what medium did it take place in, and in what medium should it be revealed?
Public conversation in digital media is dead easy. That's characters exchanging @ replies on Twitter, or alternating comments on a forum/blog/Facebook post, photo, or pretty much anything else that allows comments. Just be very careful not to inadvertently use the wrong character to say something when you're switching it around like that. It's embarrassing to you and confusing to your audience.
Private conversation is harder. That takes you back to the same questions from the Conveying Action post. Who is providing the audience with the information, and why? If the dialogue occurs in a recorded medium -- email, say, or a taped phone or video call -- then you need to give an incentive for a character to tell the audience about it through that character's established means of communication. Or you can do some hand-waving that allows the conversation to be revealed inadvertently. The much-used security flaw in a website that reveals private information, the hacked email account, and so on.
There is a third category in which public vs. private doesn't really matter; that's dialogue that happens between two characters who are just... talking. In person, old-school. This is almost all dialogue in other media -- novels, films -- with the odd phone call thrown in for good measure. If a conversation was face-to-face, your options amount to posting video or audio of it from one of your characters, having it occur during a live event and ensuring it will be eavesdropped upon, or having a character describe it later on in another medium.
Note that if you choose to have a character talk about a conversation after it's occurred, you don't have to convey it in a novelistic format. You can, if it's in keeping with the character. But you can also go simple, sticking to the character's takeaways from the conversation, but leaving out the actual words each party spoke: "Talked to Sonny. He says he's in, but I don't know if we should trust 'im. Got a bad feeling about this."
Talking With Your Audience
Dialogue between the character and the audience is the easiest of them all technically, but it takes the most will and endurance to genuinely follow through. It sounds simple. You just... talk to your audience, and then listen, and respond. The vectors are the social media choices you've made for the character. Comments on the platform of your choice -- blogs, Flickr, Facebook. @ replies back and forth on Twitter. Email exchanges. IM messages. This kind of dialogue is what turns a transmedia experience into a performative art. When you do it well, this is one of the deep conductive circuits for your lightning in a bottle.
Dialogue between a character and the audience has limited narrative use, though. Conveying character, absolutely. Fostering deeper engagement, you betcha. But it has limited function for advancing plot; you can't be sure what or when your audience will say the thing you're looking for to a character -- or whether anyone will at all.
Structurally, it's irreplaceable to allow and use dialogue with your audience as much as possible. And if you're making the kind of experience where your audience need to solve problems for your characters, this kind of two-way dialogue is generally instrumental in making that work. But it's smart not to rely on anything too specific coming out of this sort of open-ended dialogue. (And of course it doesn't scale well to experiences with hundreds of thousands of players.) Always have a B plan.
Take it away, commenters. What other issues are there in using dialogue for transmedia? And how have you solved them?