FAQ: Must all answers be referenced?

Question

How strict should we be about references?

When someone makes a claim, should we require them to support that claim with a source? If so, to what extent should we go? Must all claims be referenced or just some?

Answer 1

Wikipedia has had a huge influence over the development of Stack Exchange. This is another instance where we steal page from Wikipedia's book. After all, why reinvent the wheel?

The Wikipedia community relies on the No Original Research core policy to combat unsubstantiated claims from finding their way into articles:

This page in a nutshell: Wikipedia does not publish original thought: all material in Wikipedia must be attributable to a reliable, published source. Articles may not contain any new analysis or synthesis of published material that serves to advance a position not clearly advanced by the sources.

The very purpose of this site, as defined by the FAQ, is to combat unsubstantiated claims:

Skeptics - Stack Exchange is for skeptics, rationalists, free thinkers, or anyone who questions pseudoscience. Skeptics is about applying skepticism — it's for researching the evidence behind the claims you hear or read.

The voting system of Stack Exchange is largely meant to relax any need for specific policy regarding what constitutes a valid answer (and by and large it accomplishes this) — however, due to the nature of Skeptics, the community needs to enforce the idea of no original research to encourage healthy voting.

Users are required to reference all significant claims they make in their answers.

There are some types of questions that we can safely answer without needing references, however, such as claims that blatantly violate some laws of nature or known scientific facts (around high school level). For example, debunking a claim about a perpetuum mobile, linking to Wikipedia's article about the laws of thermodynamics might be advisable, but only for the reader's convenience.

Bad:

• "...since I have personally experienced it numerous times"
• "Anecdotally, I've seen it..."
• "I heard that it was also caused by ..."
• "I'm not sure if this idea comes from some research"

Good:

• "There is a fairly comprehensive article on the topic at..."
• "A recent Argonne National Lab study concluded that..."
• Even better, multiple sources

_{Original answer by Renesis and edited by Borror0}

Answer 2

I think there is room for some more explicitly-mentioned exceptions to the rules described in the current policy. Despite me approving of the current answer, I see people (including me) getting pinged by moderators and other regular users in cases where I think references are not necessarily required.

[Disclaimer: I have a weird conflict of interest, as I happen to have been the person who originally asked this question, so I have the power to change the accepted answer, but now it is an official FAQ question, and I don't want to abuse that power. Further, I am 99% happy with the current answer, but I want to suggest a tweak - I wanted to check if it was controversial before I blundered in with the edit button.]

Consider this fictional question about a real claim I heard as a school-kid:

I heard from my school friends that if you are asleep and you dream that you die, you actually die! Is that true?

Now, consider these fictional answers:

Answer 1:

When you dream, during the REM cycle, blah de blah, REM atonia makes the voluntary muscles blah blah, except in pathological cases blah blah, famous scientist, in an article published in Nature magazine, blah, blah.

Based on this understanding, I cannot see how it would be possible for the dream to influence your autonomic system to cause you to die.

Answer 2:

If it were true that people died whenever they dreamt about dying, then no-one would ever know that is what they were dreaming about. It is something we could never know was true (at least based on current technology.) Therefore, whoever first said it was true was making it up.

Answer 3:

Last week, I dreamed that I died. In my dream, my head got chopped off. I didn't even wake up, and kept dreaming. I am still alive today. Ask some of your older friends and family, and I am sure you will find at least one of them has also dreamed they died.

Based on the current policy, all three answers suffer from lack of references.

The first one has references, but not to the big claim in the last sentence, which ties together all the other claims and applies it to the question.

The second has no references at all, and the third is (gulp) little more than a personal anecdote!

Despite this, I fear that, under the current system, the first one would probably sneak past our filters, by having at least some references, while the second and third would get stomped on. At the same time, I think that the third is actually the most convincing argument, followed by the second.

So here are my requests:

1) That logical argument - i.e. drawing conclusions using logic based on agreed premises - be accepted without requiring references.

The premises themselves should be subject to the normal referencing rules - i.e. not required in answer 2, in this dream example, because it only relies well-known facts about dreaming.

2) That we explicitly mention that personal anecdote is permitted where it provides just the single data point required to disprove an "all people have this property" claim. I guess any such claim may be subject to others accusing the answerer of being mistaken or lying, but in many cases, where the claim is not extraordinary, I think it provides a good response.

I am not, for a second, suggesting that an "I was cured by X." anecdote provides reliable evidence for a "X cures people" claim. That sort of statement requires statistical support, but an "All people have this property" only requires one counter-example to be disproven.

What do people think? Are these reasonable adjustments to the current policy.

(No, the irony that this answer has no references has not escaped me.)