An intriguing new species in the world of online collaborative journalism has just been hatched. Assignment Zero is an experiment in “crowdsourcing”—that is, enlisting large groups of contributors to research and report on news and trends. Its organizers describe the project as “pro-am” because it relies on professional as well as citizen journalists.

Here’s how one of Assignment Zero’s founders, NYU journalism professor Jay Rosen, explains the idea:

“Can large groups of widely scattered people, working together voluntarily on the net, report on something happening in their world right now, and by dividing the work wisely tell the story more completely, while hitting high standards in truth, accuracy and free expression?”

Last summer Rosen proposed a similar project called NewAssignment.net (which we wrote about here). He also popularized the phrase “the people formerly known as the audience” to describe how Web site users are increasingly in the driver’s seat.

For editors and publishers who are trying to convince audiences to participate in their Web sites (and who isn’t?), it will be instructive to stay tuned as this project confronts such challenges as:

• How to organize and supervise an enthusiastic but possibly unruly crowd of amateurs in a virtual newsroom.
• How to coach an enthusiastic but possibly unskilled crowd of amateurs to create raw copy of reasonable quality.
• How to assess the credibility of these citizens.
• How to attract enough professional volunteers to turn the crowd’s contributions into coherent coverage. (And, incidentally, how to address the backlash from pros who don’t appreciate this push toward unpaid labor.)

In fact, Rosen issued a help-wanted call on his blog yesterday: It seems they’re getting plenty of “ams,” but they could use a lot more “pros.” If you’d like to watch the adventure of “open Web publishing” unfold from the front lines, here’s how to get involved.