The rise of Wikipedia and other communally aggregated reference materials on the internet has created a new set of challenges for educators: How accurate or reliable are these sources for student research, and what kind of policies should educators set regarding their use?

The emergence of Wikipedia and other similar online reference tools is too recent a phenomenon for most educators who spoke with eSchool News to have formed clear policies that address these sites, and opinions vary widely as to how useful or reliable such tools are for student research. But the educators we spoke with did agree on one thing: No matter what approach schools take, the use of these resources and their growing popularity underscore the need for students to learn and practice solid information-literacy skills.

"Wikis" are collaborative web sites that represent the ongoing, collective work of many authors. Similar to a blog in structure and logic, a wiki allows anyone to edit, delete, or modify content that has been placed on a site--including the work of previous authors--using only a browser interface.

The most popular and well-known of these sites is Wikipedia, an online encyclopedia that allows anyone to post a new entry or edit a previously existing one. Drawing on the knowledge and experience of a vast community of users, Wikipedia boasts approximately 3.2 million articles in more than 200 languages. Since its launch in 2001, it has grown into a clearinghouse of free information on topics ranging from medieval art to nanotechnology.

But critics say its strength--the fact that anyone can post or edit a listing--is also its greatest weakness. Unlike content published in newspapers, books, and other traditional media, Wikipedia material can be submitted by just about anyone, regardless of his or her knowledge of the subject matter--and often without having to volunteer any identifying information.

This lack of accountability was demonstrated in November when John Seigenthaler, a one-time administrative assistant to Robert Kennedy, complained in an op-ed piece published in USA Today that a biography of him on Wikipedia claimed he had been suspected in the assassinations of the former attorney general and his brother, President John F. Kennedy. The erroneous, even slanderous, information reportedly appeared on the site for about four months before it was removed.

Less than a week after Seigenthaler's op-ed piece was published, Wikipedia tightened its submission policy. The site now requires users to register before they can create articles, said Jimmy Wales, founder of the St. Petersburg, Fla.-based service. But site visitors still will be able to edit content already posted without registering.

Wales said he hopes the new registration requirement will limit the number of articles being created. While it won't prevent people from posting false information, the new process will make it easier, he said, for the site's 600 active volunteers to review and remove factual errors, slanderous statements, and other material that runs afoul of Wikipedia policy.