Wiki
On a wiki, people can write pages together to add to the information. If one person writes something wrong, then the next person can correct it. The next person can also add something new to the page. Because of this, the page gets better whenever someone changes it. If someone writes information that is very obviously wrong, and the person actually wanted to vandalise, it would be changed by administrators, and the person will not be able to change the wiki anymore. Pages are watched closely.