I love what tiny gigantic has written in this great short post about designing by writing (or the non-iterative design process). I agree wholeheartedly, although I think of writing as part of design to be accretive and/or iterative.
A few choice bits from the entry:
[W]hen someone asks you why you used green, or why you included that crumpled-paper background, or why there’s a bird in the logo, you’re gonna need to know. What’s more, you’re going to need to be able to articulate it in a way that makes them care. I’ve been in graphic design classes in which I’ve asked students presenting their work why they did what they did. And 90% of them have said something like: “because it’s like, I don’t know. It’s like I thought that color looked super good right there. And I like birds.”
...
It’s not enough to make pretty things. You’ve got to be able to talk about them, to present them, to parse their meaning. And the truth of it is that if you can’t articulate what the thing you’re making means, you’re gonna have a helluva time making it mean something to someone else. Which is a problem, because that’s the job.
I like to write before I do anything related to interaction design. I like to read, gather and summarize loads of user feedback, to talk among my team about ideas we have to solve problems, and then distill it all into statements of the problem, proposals for design concepts, and stories (use cases and scenarios). This is all the intellectual work of design. Where I work now, it happens in a wiki article with users adding paragraph comments, all before I start to sketch. Then it continues to happen when my team annotates sketches.
In any case, the point is that the thought process that leads to design is what's important, and if there is none, then maybe writing can help in that case. Perhaps not everyone needs to write so much as communicate and capture in some way, even if it's only in discussion and notetalking or what have you.
http://www.tinygigantic.com/2009/02/11/designing-by-writing-or-the-non-iterative-design-process/