The Different Types of Wikis

(http://www.techsoup.org/learningcenter/webbuilding/page4563.cfm)

Generally speaking, wikis can be divided into three basic categories: public, protected, and private.

Public

A wiki with an active and engaged community of users can come to be a valuable vault of shared knowledge that evolves and expands over time. Public wikis like Wikipedia allow anyone on the Internet to view, create, and edit pages. Although some public wikis require you to create an account before you can alter content, others let anonymous users add or change pages.

Protected

Protected wikis, on the other hand, are visible to the general public but can only be changed by authorized users. Most wikis have a designated administrator (or wikimaster) who grants users the permissions required to edit, add, or delete information. The wikimaster also makes general rules and enforces standards of conduct to help maintain the integrity of the content.

Private

Private wikis are most often used for internal communications within a company or organization; only those who are authorized by the administrator can even view the wiki, let alone edit it.

If your organization is setting up a protected or private wiki, the designated administrator can ensure that only trusted users are allowed to contribute content or edit pages. However, if you decide to open your wiki to the general public, you should be prepared to remove undesirable or off-topic content that users might add.

This so-called "wiki vandalism" takes a few different forms; some individuals might post inflammatory content while others might delete useful information. Spammers have also been known to deface wikis by deluging them with links to commercial sites. If you do choose to build a public wiki, enlist your core community to help you police the content for inappropriate entries and create a feedback form for reporting wiki vandalism.