On Internet websites which invite users to post comments, a moderation system is the method the webmaster chooses to sort contributions which are irrelevant, obscene, illegal or insulting from contributions which are useful or informative.

Various types of Internet site permit user comments, for example Internet forums, Web logs, and news sites powered by scripts such as phpBB, a Wiki or PHP-Nuke. Depending on the site's content and intended audience, the webmaster will decide what kinds of user comments are appropriate, then delegate the responsibility of sifting through comments to their moderators. Most often webmasters will attempt to eliminate trolling, spamming, or flaming, although this varies widely from site to site.

Anarchy

Anarchy is the oldest of moderation strategies and dates back to a time when the Internet was a smaller place and people who were misbehaving could more easily be traced. This system can be seen today in Usenet newsgroups - where no message is ever censored or deleted. Unfortunately with the advent of electronic commerce the newsgroups have largely become overrun with spam and many groups are not suitable for children. Some argue that Usenet is no longer a useful communication medium although client-side solutions in modern newsreader software such as bayesian filtering techniques offer some hope. Various websites still prefer to avoid censorship entirely, mainly for freedom of speech reasons.

Supervisor moderation

This kind of moderation system is often seen in Internet forums. A group of people are chosen by the webmaster (usually on a long term basis) to act as his delegates, enforcing the community rules chosen by him on his behalf. These people are given special powers to delete or edit contributions of others and/or exclude people based on their e-mail address or IP address and attempt to 'keep the peace' within the community.

User moderation

This system allows any user to moderate any other user's contributions. On a large site with a sufficiently large active population, this usually works well since relatively small numbers of troublemakers are screened out by the votes of the rest of the community. The definitive example of a user moderation system is Slashdot.

Each moderator is given a limited number of "mod points", and they can use each one to moderate an individual article up or down by one point. Articles thus accumulate a score. The score is additionally bounded to the range -1 to 5 points. When viewing the site, a threshold can be chosen from the same scale, and only posts meeting or exceeding that threshold will be displayed. The Slashdot system is further refined by the concept of karma - the ratings assigned to a users' previous contributions can bias the initial rating of contributions he or she makes.

Moderator powers are assigned for short times based on various factors including karma, and a meta-moderation system (whereby users moderate the moderators) to ensure moderators are doing a good job.

External links

• EFF Blue Ribon Campaign - A site dedicated to fighting Internet censorship
• Slashdot - A definitive example of user moderation
• phpBB - an Internet forum system offering supervisor moderation