I’ve previously posted about three new “data-journalism” sites that have opened-up shop this summer — Vox, Five-Thirty-Eight, and The New York Times “Upshot.”

Today, The Washington Post announced that they,too, are joining the party with a site called Storyline. It doesn’t actually have a web address yet (it’s officially launching next week), but it can be found on Twitter and Facebook.

The Post did release this preview video, which doesn’t really tell you much about Storyline is actually going to do, but it does give the impression it might be a little more narrative-driven then Five-Thirty-Eight and The Upshot. Vox’s emphasis on narrative is what is clearly making it the stand-out among this crowd, so it will be interesting to see what Storyline does….