Wiki science/Self Healing

Self healing is the ability of a Wiki to heal quickly after vandalism or other damage.

For a wiki to be successful, it must have a vibrant user base. Assuming this, then the users will be able to repair any damage done to the Wiki.

Vandals
A "Vandal" (Also called a "WikiTroll" (Not to be confused with a straight up troll)) is a malicious user who deliberately attempts to ruin a wiki. The "malicious" part is important: vandals are deliberate attackers, whereas newbies who don't know the site but mean well may also inadvertently cause damage.

Common vandalisms are:
 * Blanking or removing text from pages
 * Replacement of articles with something they know is less desirable.

Good spirits
A good spirit is a contributor to a Wiki who goes out of their way to make the Wiki a better place. This would include maintaining a large watch list, which they monitor closely, and checking the recent changed articles as well. They look for any article they can help with, keeping an eye for typographical errors, formatting issues and especially for any signs of vandalism.

They are constantly on a the lookout for their opposite, the Evil Spirit. It is a shame that a good spirt must spend so much of their time cleaning up after evil spirits when they could be contributing in so many other productive ways.

A good spirit should not be confused with a typical user who just reads or makes contributions with little concern for the actions of others.

Damage
If an Evil Spirit causes damage to the Wiki in some way, then a Good Spirit can repair the damage. Wikis are self healing if the good spirits outweigh the bad. Wikipedia has many Good Spirits.

A good way of defining how well a Wiki can self-heal is the ratio between users that are good and those who are evil. The ratio of Evil Spirits to Good Spirits can be defined as

$$\frac {U_{good}} {U_{evil}}$$

where $$U_{good}$$ is the number of good users, and $$U_{evil}$$ is the number of bad users. $$P_{useful}$$ is the amount of useful pages, that is, subtracting all Talk Pages, User Pages, etc.

An optimal self-healing Wiki is one where

$$\left( U_{evil}A_{Pdamaged} \right) \le \left( U_{good}A_{Pcontrib} \right)$$

$$A_{Pdamaged}$$ and $$A_{Pcontrib}$$ are the average pages damaged and average pages contributed, respectively.

If the above formula does not hold true, your Wiki is overrun with bad pages and Evil Spirits.

Evil Spirit users should be dealt with as swiftly as possible.

One way to deal with Evil Spirits is to ban them. This requires a conscious human being who has admin powers to ban them, which can take hours. Some methods of dealing with vandalism could be restricting the amount of edits that a user can do for a while, possibly augmented with a trust system: having a review on the quality of an edit, which functions as a 'karma' rating where high-rated edits allow the user to be less restricted.