Wikipedia is considering a basic change to its editing philosophy to cut down on vandalism. In the process, the online encyclopedia anyone can edit would add a layer of hierarchy and eliminate some of the spontaneity that has made the site, at times, an informal source of news.

It well could bring some law and order to the creative anarchy that has made the site a runaway success but also made it a target for familiar criticism.

The idea, which is called “flagged revisions,” has only been possible in the last few months because of a new extension to the software that runs Wikipedia. It is sure to be a hot topic here at Wikimania 2008, in Alexandria, Egypt, because it promises to enact a goal for “stable versions” of articles that has long been championed by Wikipedia’s founder, Jimmy Wales.

An administrator at the German Wikipedia, where the first large-scale experiment is happening, will give a talk Friday on how it’s going.

The German site, which is particularly vexed by vandalism, uses the system to delay changes from appearing until someone in authority (a designated checker) has verified that the changes are not vandalism. Once a checker has signed off on the changes, they will appear on the site to any visitor; before a checker has signed off, the last, checker-approved version is what most visitors will see. (There are complicated exceptions, of course. When a “checker” makes a change, it appears immediately. And registered users, who make up less than 5 percent of Wikipedia users, will also see “unchecked” versions.)

Approximately 60 percent of the more than 750,000 German articles have been checked, and thus are under watch in the future. There are approximately 3,000 checkers, though Mathias Schindler, one of the administrators of German Wikipedia, says he expects the numbers to grow, since the only requirement is that someone have made a total of 300 edits, none of them vandalism.

The Germans who are implementing the idea stress that the checkers are not a heavy hand, but are doing the most cursory examination to see that no curse words or obvious non sequiturs have been added. While some revisions can wait a day, usually they only take minutes, as checkers like Mr. Schindler spend hours going through lists of changes to approve.

Also, they point out that edits that haven’t been approved are still in the system and show up to anyone who later wants to make edits. So contributions would not be lost or overwritten as they wait for a checker to approve them.

Administrators at Wikipedias in other languages, as well as people at the Wikimedia Foundation, said they were watching the German experiment carefully expecting that some version of it would migrate to the other versions.

Ultimately, the checkers hope for their own obsolescence. If vandals, online or off, cannot show their work to the world, perhaps fewer vandals will take up the task.