Audience data is the new currency in journalism. I don’t just mean the traditional Costco buy-in-bulk kind — “our readers are 52 percent male, 46 percent over $75,000 household income, 14 percent under age 35,” and so on. I mean data that looks at how individual readers interact with individual pieces of content. And beyond that shift there’s also the move from observational data — watching what your audience does — to experimental data, testing various ways of presenting or structuring content to see what works and what doesn’t.

My desire for more experimental data is one reason why I’m very happy to point you to a new resource for sites built on WordPress (like this one): a new Headline Split Tester plugin, built by Brent Halliburton and Peter Bessman, two Baltimore developers.

Not sure if you want a straight, newsy headline or something with a little more pizzazz? Something keyword-dense and SEO friendly or something more feature-y? This plugin lets you write two headlines for each post and have them presented at random to readers. The plugin records how often each version of the headline has been clicked and, once it has enough data, swaps full-time to the most effective one.

If you’re in the kind of operation that has regular debates over headline strategy, here’s a great way to test it. (Although note that this is measuring clicks on articles within your site — it doesn’t tell you anything about the SEO effectiveness of a headline. You’d have to wait for Google data for that.)

We have lots of debates over the appropriate role of audience metrics in journalism. But personally, I’d rather have those debates armed with as much data as possible. If you want your site to be filled with puns and plays on words instead of SEO-friendly nouns, fine — but it’s worth knowing how much of a traffic impact that decision has when you make it.

I’m happy to say we apparently played a small role in its creation: Halliburton writes that he was inspired by an old Lab post that described how The Huffington Post uses A/B split testing on some of its headlines:

Readers are randomly shown one of two headlines for the same story. After five minutes, which is enough time for such a high-traffic site, the version with the most clicks becomes the wood that everyone sees.

Give it a try — and if you’re a PHP coder, try to make it better, as patches are welcome. (Another, more ambitious A/B testing project for WordPress, ShrimpTest, is also in development and in preview release.)

Halliburton (who runs Cogmap and Deconstruct Media) and Bessman (who’s an engineer at marketing firm R2integrated) built the plugin in as 2010 a way as possible: at last weekend’s Baltimore Hackathon, where the plugin won a prize for best prototype. Have a good idea, bang out code in a weekend, share it with a potential audience of millions using the same platform — that’s the promise of open source and collaboration in a nutshell.