Wikipedia:Why most sentences should be cited

It is best to cite each statement using a reliable source instead of containing uncited statements that may eventually get deleted.

Wikipedia:Verifiability policy requires that the material must be attributable to reliable sources. This means others must be able to check that the material comes from a reliable source. When the material is attributed to a source by using an inline citation, anyone can check to verify the statement by reading the source.

The material must also be neutrally written and not contain original research. It is better to place each citation closely where it verifies each material than use one citation at the end of a paragraph because the content may be rearranged or anyone may believe the uncited content is unsourced. Without placing each citation where it verifies each material, it could lead to concerns of original research and eventually deleted content.

Whistleblower's Disease

A (once) rare malady where a person suspected of going to the press with alarming news suddenly dies in odd circumstances. These circumstances can include:

• Suicide by shooting oneself several times in the back of the head.
• Falling off a cliff.
• Umbrella pellet radiation poisoning. (See also Gallium)
• Hanging in a prison cell with toilet paper.
• Sudden brake failure.
• The old "Toaster in the Tub" trick.

Maintaining text–source integrity

One of our policies is on "text-source integrity". That policy rightfully states (as of this stable revision): "The point of an inline citation is to allow readers and other editors to check that the material is sourced; that point is lost if the citation is not clearly placed. The distance between material and its source is a matter of editorial judgment, but adding text without placing its source clearly can lead to allegations of original research, violations of the sourcing policy, and even plagiarism."

So far, so good, and in fact I have no problem with that policy. However, my understanding of it differs from that of some others; namely, I see this policy as sufficient to warrant the requirement of citing every sentence, even in cases where all sentences in question use the same reference. After all, on wiki, people can split paragraphs, move content, insert new text, referenced or unreferenced, and unreferenced sentences can lead to text-source integrity problems.

Unreferenced material

Consider the following example:

The sun is pretty big. The moon is not so big. The sun is also quite hot.

Notes

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It seems fine at first glance. We can assume that all three sentences come from the same cited source, right?

Wrong. How can we make such assumption in a project which "anyone can edit"? Without looking at the history of the article, one cannot be certain that all three sentences were inserted by the same author, using the same source. What if they were written by editor A, and editor B came along later, adding a new, relevant, referenced sentence, but with the ref for the third sentence only? What if the first and third sentences were written by editor A, with a reference, but the second, unreferenced sentence was inserted by editor B later?

Let's however assume that all three sentences, with the one, end-of-para reference, were written by a single editor. Let's see what can happen later, in Case Study 1:

The sun is pretty big. The moon is not so big.

The sun is also quite hot.

Notes

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Here, we have editor B coming and deciding that the paragraph would be better split into two, or perhaps moving the third sentence elsewhere. And what happens? We have a new, unreferenced paragraph. Now, can readers trust unreferenced paragraphs? Heck, WP:V clearly allows for their removal...

Case Study 2

The sun is also quite hot. The sun is pretty big. The moon is not so big.

Notes

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What if editor B simply decides to change the order of sentences, but keeps the citation with the intended sentence? Now the later sentences look simply unreferenced.

Case Study 3

The sun is pretty big. The moon is not so big. The sun is also quite hot.

Notes

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What if our editor B decides that the second sentence needs a reference, and inserts one that is good for this sentence, but not for the first one? If the original reference supported all three sentences, it no longer does – and the logic of consecutive sentences supported by the last reference suggests that the first sentence (unreferenced) is supported by the ref in the second sentence (incorrect).

Case Study 4

The sun is pretty big. The moon is not so big. The sun is yellow and the moon is gray. The sun is also quite hot.

Notes

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What if editor B inserts an unreferenced sentence into our paragraph? How is the reader supposed to know which sentence comes from the end-of-para reference, and which has been inserted later?

Wikipedia articles should be trustworthy as "seen". They should not require readers to check edit history. Even then, it's somewhat understandable if one wants to verify that the article is stable; that just takes a few seconds of looking at the recent history, with no need to compare revisions. But with insufficient citations, an editor has to track down the exact diff adding content, to see if it came from the same editor who added end-of-para reference. And frankly, even then you have to assume good faith or verify all but the referenced sentences with a source to be sure that that editor did not add any sentences that are not covered by that source.

Yet my proposals to clearly state that every sentence should be referenced, cases of Wikipedia:You don't need to cite that the sky is blue exempt, have been rejected by the community not once but twice: uno, due.

Your confused editor, signing off.

Examples

In case anyone thinks my example concern is theoretical, here's a perfect case study:

• new paragraph, with citations, added (all sentences referenced to the same source: Kościuszko left for the United States, through [[Stockholm]], Sweden, and London, departing from [[Bristol]] on 17 June, to arrive in Philadelphia once more on 18 August.<ref name="psb437"/> Despite being welcomed by the American populace, he was viewed with suspicion by the United States government, at that time controlled by the [[Federalist Party|Federalists]], who disliked Kościuszko for his previous association with the [[Democratic-Republican Party|Democratic-Republican faction]].<ref name="psb437"/>)
• paragraph merged with the subsequent one, also using the same citations
• citations removed, no explanation provided – presumably cleaning "excess references" because someone doesn't think all sentences need to be referenced to the same source
• paragraph broken, resulting in an unreferenced paragraph
• unreferenced paragraph complained about at FAC
• citations restored (time finding them wasted: 10 minutes; time to compile this example: 20 minutes; net loss for Wikipedia: one DYK I could've written instead)

I am not going to waste more time citing further examples, but I've seen this happen enough times. Someone (me...) references sentences. Someone else copyedits the article, removing what they think of are excess citations. AND/OR Someone else breaks paragraphs, creating unreferenced ones. People complain, article is seen as unreferenced, even though someone either took the time to properly reference every sentence (or didn't...). Teeth grinding ensues.

See also

• Wikipedia:Citation underkill An essay suggesting to cite every sentence
• Wikipedia:Don't hijack references A short but important reminder
• Wikipedia:Citation overkill This discusses why numerous citations after a single sentences are too much, not why one would not want to cite every sentence
• Wikipedia:Bombardment A similar argument to the one above
• Wikipedia:You don't need to cite that the sky is blue A classic argument on that not everything needs to be cited
• Wikipedia:When to cite and when a source may not be needed A companion to WP:BLUE, listing few additional reasons why citations are not necessary
• Wikipedia:The Pope is Catholic Another companion to BLUE
• Wikipedia:You do need to cite that the sky is blue A counter-argument to BLUE
• Wikipedia:Likely to be challenged A citation after every sentence is not always required by policy; however, you are permitted to add more citations than are strictly required.