Wikipedia:Check your facts
From Freepedia
Write stuff that is true; check your facts. Don't write stuff that is false. This might require that you check your alleged facts.
This is also a basic part of citing good sources...even if you think you know something, you have to cite references anyway to help the reader check facts and look for more information. In searching for good references to cite, you might even learn something new.
A corollary to fact-checking is to be careful about deleting material that may be factual. Frequently editors will incorporate substantive material without providing a reference. If you should be inclined to delete something from an entry, consider whether or not it may be profitable to check the facticity of the content first. Of course, if material is factual, i.e. substantiated and cited, be extra careful about deleting. An encyclopedia is, inter alia, an organized collection of facts, so consider each fact provided as potentially precious. Is it possible to re-contextualize a fact? Is the context or overall presentation the issue? If another editor provided a fact, there was probably a reason for it that shouldn't be overlooked. Of course, it is not true that everything an editor adds must be preserved. But be careful about deleting substantiated, relevant material.
A further corollary to fact-checking is to examine entries you have worked on subsequent to revision by others. Have facts been omitted or deleted? It may be the case that you failed to provide sufficient substantiation for the facts, or that the facts you incorporated may need a clearer relationship to the entry. In either case, it may be necessary to restore facts to the entry. Protect your facts, but also be sure that they are presented meaningfully.
See also: Wikipedia:Verifiability
