OK, so I had previously found a summary of Kathy Sierra’s 2007 SXSW talk, and was excited to see that she spoke about ensuring the humanness of our help documents, FAQ, and other support stuff.

But after a little more digging, I found some great stuff that she wrote earlier that includes primary research citations. (This is the kind of stuff that’s good to have when you have to defend these ideas inside a big corporation.)
In 2005 Kathy wrote Conversational writing kicks formal writing’s ass. Some highlights from that include:

A study from the Journal of Educational Psychology, issue 93 (from 2000), looked at the difference in effectiveness between formal vs. informal style in learning. In their studies, the researchers (Roxana Moreno and Richard Mayer) looked at computer-based education on botany and lightning formation and “compared versions in which the words were in formal style with versions in which the words were in conversational style.”
Their conclusion was:
In five out of five studies, students who learned with personalized text performed better on subsequent transfer tests than students who learned with formal text. Overall, participants in the personalized group produced between 20 to 46 percent more solutions to transfer problems than the formal group.”
They mention other related, complimentary studies including:
“… people read a story differently and remember different elements when the author writes in the first person (from the “I/we” point of view) than when the author writes in the third person (he, she, it, or they). (Graesser, Bowers, Olde, and Pomeroy, 1999). Research summarized by Reeves and Nass (1996) shows that, under the right circumstances, people “treat computers like real people.”
So one of the theories on why speaking directly to the user is more effective than a more formal lecture tone is that the user’s brain thinks it’s in a conversation, and therefore has to pay more attention to hold up its end! Sure, your brain intellectually knows it isn’t having a face-to-face conversation, but at some level, your brain wakes up when its being talked with as opposed to talked at. And the word “you” can sometimes make all the difference.

And then in 2007 she wrote Your user’s brain wants a conversation. An excerpt from that post:

Which would you prefer to listen to–a dry formal lecture or a stimulating dinner party conversation?
Which would you prefer to read–a formal academic text book or an engaging novel?
When I pose this question to authors or instructors, I usually hear, “You think the obvious answer is the dinner party and the novel, but it isn’t that simple.”
Followed by, “It all depends on the context. I’d much rather hear a dry formal lecture on something I’m deeply interested in than listen to inane dinner party conversation about Ashlee’s lip-syncing blunder.”
But here’s what’s weird–your brain wants to pay more attention to the party conversation than the formal lecture regardless of your personal interest in the topic.
Because it’s a conversation.
And when your brain thinks it’s part of a conversation, it thinks it has to pay attention… to hold up its end. You’ve felt this, of course. How many times have you sat in a lecture you really needed and wanted to pay attention to, but still found it hard to stay focused? Or how about the book you can’t seem to stay awake for… finding yourself reading the same paragraph over and over because you keep tuning out–despite your best effort to stay with it?
But here’s the coolest (and for me, the most fascinating) part of all this:
When you lecture or write using conversational language, your user’s brain thinks it’s in a REAL conversation!

This is some very cool stuff! Anyone have any success stories to share in making the change to conversational language in technical support content?