Assume that when an editor makes an edit, it was to help the wiki, not to damage it.
The reason for this policy is because All Editors Are Created Equal, and you must not assume that new editors are vandals, or that you know better than them.
For example, if a user empties a page, you should assume it was an accident or test rather than a deliberate act of vandalism. You can correct the edit, and ask the user to be more careful next time. You should not tell off or shout at the user.
If a user removes content from a page, assume it is an accident or test
If a user breaks a page layout or complex template, assume it was an accident
If a user adds incorrect information, assume that they believe it is correct, and discuss it on the talk page to figure out what the content should say
If a user adds a small or useless piece of content, do not instantly delete it
If a user makes a number of spelling/grammar errors, assume it is an accident and correct the content If you are sure that a user made a non-constructive or incorrect edit, then feel free to correct it. If there is a disagreement, you should use talk pages to explain yourself and give others opportunity to do the same. You must work together with the rest of the community to come to a consensus on the correct content for this wiki. This can avoid problems and prevent arguments from escalating.
Remember to be patient with newcomers. They may not know how to edit a wiki or what's supposed to be added as content.
What is not good faith
Actions inconsistent with good faith include deliberate vandalism and lying. If you have spotted obvious vandalism by any user, then you know it was not good faith and you can remove the offensive content without prior discussion.
Vandalism should be reported immediately to an Administrator who can work to prevent it from happening again. Administrators should remember that All Users Are Created Equal, and try to help the user understand why they shouldn't vandalise.