It seems to be a recurrent theme here that someone makes a statement that seems perfectly reasonable, someone else demands a reference to support the claim, and then there is no reply.

I'm starting to wonder if this is a smell, that it shows there's a genuine question to answer, but that the two sides are sufficiently entrenched that they will argue past each other rather than trying to find the truth.

I don't know how common this really is, although I feel like I see it a lot. Some I've run across lately are on
* AsFastAsCee
* SufficientlySmartVirtualMachine
* WikiPedia, where the pattern is called ''[citation needed]''

See if you can find more examples, and maybe identifying the pattern (although it might not be a Pattern, AntiPattern or even anti-pattern) will help to generate more light than heat.

--------

Somebody has been sticking this in my text of late. 

''Wow, and who is the one always wanting proof and evidence... Top is. Always claiming for someone to prove it or show for it. Hmm.''

I have at least these problems with it:

* They mostly do it to me, not others. Double-standard.
** You'll mostly see it for your own arguments because you're often guilty of attempting to shift burden of evidence when asked to defend them.  Placing 'DemandForEvidence' next to your claim makes it clear that it is YOUR responsibility to defend your claim.  
** ''This is very weak. If my "sin" is shifting the burden, then use a tag to point that out where it actually is. Instead, it appears to be twisted revenge.''
** A tag is used: [DemandForEvidence].  When you actually start answering these demands, perhaps you'll earn the right to be treated as a respectable debater again.  
** ''That sounds like an outright threat to me. And, it you don't apply it equally to those you agree with. In other words, a double-standard.''

* I don't want to defend every claim I make. They are often not pivot-able to my main point but instead illustrative.
** Don't make claims you aren't willing to defend, and don't do to others that which you don't want done to yourself.  Ask yourself what you are doing very carefully 
** ''I, nor anybody else is obligated to prove every objective claim they make unless they repeatedly depend on it.''
** You, and anybody else, is only obligated to '''be willing''' to defend the claims you make.  If you don't "depend on it", then the claim constitutes a conclusion all by itself rather than a premise, and you need to be willing to defend your conclusions, too.
* I also often require that the demander claim that they are legitimately skeptical of the claim so that I don't waste time on things we don't really disagree about. This is to reduce ThreadMess. It's an often-used red-herring debate tactic to tie somebody up on things you don't actually dispute.
** Don't twist the scenarios, TopMind - You demanded they ''disagree'', not that they merely be skeptical.  And considering how often you love to get into fights about perceived insults or proper metrics or anything BUT proving your claim on the subject matter, I think YOUR requiring that the demander state skepticism first is just YOUR red-herring debate tactic used to distract from the subject matter at hand.  You should be twice as willing to focus on the subject matter as you are on perceived insult or rudeness, or you should at least be able to handle both at the same time; anything else is remarkably amateurish and childish.
** ''I don't see much distinction between "disagree" and "skeptical". Otherwise, it is a reasonable request that I think most WikiZen''''''s will agree with. I stand by it.''
* It is not polite. If you have to do it on every sentence, then you are too demanding. Otherwise, simply ask, "I would like to see more evidence for your blue monitor claim above". That's the civilized way to do it.
** In my experience you've never answered a request for evidence, polite or otherwise - at least not with actual evidence.  In my experience thus far, you either: (a) don't answer, (b) attempt to shift burden of proof and attempt to make them disprove your claim, (c) say it is true in your experience, (d) blow up and yell about science, (e) demand that the other person state they disagree and otherwise drive conversation away from answering the request for evidence, (f) answer a different question entirely, (g) present a 'scenario' that does nothing at all to prove your claim, (h) falsely whine and complain that burden of proof is being improperly shifted to you.  Etc.  Perhaps putting 'DemandForEvidence' in your paragraphs is less an attack against you than it is a warning to all who follow.
** Further, YOU should not expect politeness from others.  Your arguments are often full of insults, both subtle and obvious, and probably some each of unintentional and intentional.  People notice these things.  If you wish politeness, you should first offer it, and doing so may require you break some habits of yours that you're probably not even aware you possess.
** ''We've seen phrases such as '''eff off''' and '''bulls**t''' and '''arrogant''' come from Top. Hypocrisy once again. Top,  self reflect - look in the mirror before talking.''
** I adamantly disagree. I am only rude in response to rudeness, and I am careful to not escalate except in extreme conditions. I do attack ideas with vigor, but that is a far lessor "sin" than attacking people. I rarely attack people directly, and only as a response to an extreme attack on me first. I never purposely draw first blood. You are the spitful spiteful one, not me. I will agree to stop all personal insults if you do. (Okay, I have misued "bulls**t" at times. I'll try to cut back on that one. Still, it is attacking a statement, not a person.) -- top
** The greatest "sin" someone can commit on a public forum is giving bad or negligent advice under the guise of an expert.  People like you who don't do their homework and neglect to vet the advice they place on public forums for other people to follow commit, to MY mind, '''a crime for which they should be morally, legally, and fiscally responsible'''.  Doctors can be sued for giving bad advice; you should consider yourself in the same situation.  You commit such crimes on a regular basis - you don't even bother proving your points before putting them out there.  Compared to that, the "sin" of attacking you is ''nothing''.  If there was such a thing as a 'license' to be a programmer, I'd move to have yours revoked for your devil-may-care "I'm making it for the masses" attitude you display on such pages as TypesAreSideFlags.  Not all rudeness comes in sputtering insults.  Your most pervasive rudeness comes in form of your arrogance, hypocrisy, and nearly criminal behavior.
** ''In that case, you are the biggest sinner because you claim objective benefits without cited scientific evidence. I don't explicitly claim objective benefits to my favorite techniques. (This is not the best place to debate who has the best science. Take it to TraitsOfGoodScientificEvidence if you want to continue this discussion.) And, you are an exaggerating drama-queen: "Criminal behavior"? Pfffft.''
** I often offer proof for my statements (and I often volunteer it rather than forcing someone to ask).  You, with your typical combination of aloof arrogance and utter ignorance, typically call it 'MentalMasturbation'; I can't help that you're incapable of comprehending proof even after explanation, even after seeing the evidence and the logic - that's YOUR problem; you have to be able to meet me half way if you're ever going to comprehend a proof regarding syntax extensions or logic programming languages or understanding the relative significance of 'possible' and 'necessary'.  But I've consistently been willing to provide my evidence and my logic, at least to within the limits of DontRepeatYourself, and sometimes even beyond.  You often blame me for 'poor writing'; I blame you for 'arrogance and lack of education' that combine to make you believe you are so far above proofs you barely even grok that you think the writing is to blame.  Further, I am willing to be responsible for my advice, just as I am for my code.    Besides, within the domain of computer programming languages, and the domain of software, both of which are ''entirely'' mathematical constructs, math IS truth, so there is little need for the ''weaker'' 'empirical' evidence or observations except where claims regarding psychology, statistics, or politics are made.  So don't pretend I'm the criminal here - you're the person who acts like a whole-sale snake-oil salesman attempting to create 'solutions' that 'keep it simple' 'for the masses', despite your inability to convince anyone but yourself and the ignorant of the virtues of your solutions.  B''''''lindFoolsAndCharlatans - I've never quite figured out which one you are.  
** In any case: if you're not making any benefits of your techniques, why do so many of your statements look exactly like claims of benefits written in the English language, TopMind?  And why do you have so many pages promoting them?  Must I sprinkle ever more '[DemandForEvidence]' tags when I see you making such claims in the future?  You're practically begging for it with a statement like ''"I don't explicitly claim objective benefits to my favorite techniques."''  Or are you saying that, from you, such statements "X" should always be reworded to read "some people think X" (which is hardly a claim at all)? 
** ''Re: "I often offer proof for my statements" - No you don't. You offer (weak) evidence, not proof. --top'' 

--top

''In other words, it is okay for Top to demand '''proof''' (which has been provided) from others, but when Top is asked to show many (any) evidences or third party references - ha! No - Top has experience and we are to take his word for it.''

If I claim that Foo is objectively better than Bar, then I am obligated to provide evidence. But, I haven't. Therefore, your criticism does not apply. --top

''On the other hand, if you claim that Foo is better than Bar, and insist other people prove you wrong, then you are obligated to provide evidence.  (Qualifier, not specifically directed at top)''