"extraordinary evidence"

[billydkid]

How does that expression go - "Extraordinary claims require extraordinary evidence."? Anyway, that expression has always bothered me. It gives people making ridiculous claims a way out. The fact is for all extraordinary (as in supernatural) claims there is in fact no evidence let alone "extraordinary evidence". I would be happy with any verifiable evidence. I think to people inclined to believe supernatural BS the requirement for extraordinary evidence sounds unreasonable and close minded. I prefer to say that if you make some sort of extraordinary claim you need to have legitimate evidence to back it up. I have never seen any legitimate evidence for paranormal claims.

[kellyb]

It's just a good way of fending off the anecdotes.

[Paul C. Anagnostopoulos]

We've had this conversation numerous times. I think it was Dr. Adequate who said that extraordinary claims require just good old evidence, as you are saying. On the other hand, who the heck needs any evidence for the claim "there is a chair in my living room"?

~~ Paul

[Miss Whiplash]

How does that expression go - "Extraordinary claims require extraordinary evidence."? Anyway, that expression has always bothered me. It gives people making ridiculous claims a way out. The fact is for all extraordinary (as in supernatural) claims there is in fact no evidence let alone "extraordinary evidence". I would be happy with any verifiable evidence. I think to people inclined to believe supernatural BS the requirement for extraordinary evidence sounds unreasonable and close minded. I prefer to say that if you make some sort of extraordinary claim you need to have legitimate evidence to back it up. I have never seen any legitimate evidence for paranormal claims.

It works for me, though. If a person (like one person I'm investigating now) claims to be a world renowned vampire hunter, I want to see a corpse with a stake in its heart. That evidence, on the face at least, is a bit extraordinary. ;)

[Paul C. Anagnostopoulos]

So maybe we should say "Outlandish claims are likely to be accompanied by outlandish evidence."

~~ Paul

[RSLancastr]

"there is a chair in my living room"Evidence?

[Paul C. Anagnostopoulos]

Evidence?
An anecdote should be plenty enough evidence for such a mundane claim. :D

~~ Paul

[Beady]

How does that expression go - "Extraordinary claims require extraordinary evidence."? Anyway, that expression has always bothered me. It gives people making ridiculous claims a way out.

Not when properly used:

It would be an absolutely transforming event in human history. But, the stakes are so high on whether it's true or false, that we must demand the more rigorous standards of evidence. Precisely because it's so exciting. That's the circumstance in which our hopes may dominate our skeptical scrutiny of the data. So, we have to be very careful. There have been a few instances in the [past]. We thought we found something, and it always turned out to be explicable...


Carl Sagan (http://www.pbs.org/wgbh/nova/aliens/carlsagan.html)

My emphasis. In short, our standard of evidence should rise in direct proportion to a proposition's significance.

[Paul C. Anagnostopoulos]

In short, our standard of evidence should rise in direct proportion to a proposition's significance.
I'm not convinced. This implies that mundane or only moderately interesting scientific claims can be answered with less-than-compelling evidence. Once a claim is a scientific claim, evidence is evidence.

I think we tend to convolute the kind of evidence that a paranormal researcher needs to supply with the level of scrutiny it's going to receive afterward. How about "Extraordinary claims require good old scientific evidence, but don't expect to get away easily."?

~~ Paul

[baron]

It's just a good way of fending off the anecdotes.

Why would you want to do that?

[Paul C. Anagnostopoulos]

Why would you want to do that? [fend off anecdotes]
So we don't have to listen to 139 stories about ghosts that people think are evidence, when they are not evidence?

~~ Paul

[tkingdoll]

I'm not convinced. This implies that mundane or only moderately interesting scientific claims can be answered with less-than-compelling evidence. Once a claim is a scientific claim, evidence is evidence.



No, no, ALL scientific claims demand an extraordinary level of evidence. I think Sagan was comparing them to everyday mundane claims, like there being a chair in your living room. For that, I would simply take your word for it and it becomes fact. But for ANY scientific claim, be it paranormal or otherwise, you can't offer that little evidence.

Proving telepathy requires no more extraordinary evidence than penicillin, in fact if para researchers could come up with the same level of evidence for telepathy as Fleming did for penicillin, no-one would have a problem.

I don't think Sagan was saying one scientific claim demands more evidence than another, simply because even the simplest scientific discovery can change the world. So, if you have any claim that will change the world, you need to provide a level of evidence at the standard all other scientific claims are measured by. In the case of paranormal claims, that simply never happens.

[baron]

So we don't have to listen to 139 stories about ghosts that people think are evidence, when they are not evidence?


Either we're talking about scientific evidence, which wasn't made clear, or you don't know what evidence is.

[Paul C. Anagnostopoulos]

Either we're talking about scientific evidence, which wasn't made clear, or you don't know what evidence is.
What are we talking about, court evidence, where heresay and anecdote are allowed (more or less)? Surely the existence of ghosts is not something to be decided by court evidence. A claim about the natural world is pretty much a scientific claim, wouldn't you say?

~~ Paul

[Walter Wayne]

Part of what makes ordinary claims ordinary, is that there is already either evidence or precedent for the claim.

A chair in Paul's living room is an ordinary claim because, there is much evidence of the existence of chairs that is available to pretty much to any layman. Their presence in living rooms is common.

What makes claims of Newtonian physics ordinary, is that an extra-ordinary amount of evidence has already been provided.

What makes claims of perpetual motion devices, ghosts and such extraordinary is the complete lack of anything even remotely resembling them so far.

So yes, it is true that extraordinary claims require extraordinary evidence. It so happens that "ordinary" claims already have extraordinary evidence. To me the debate seems to be semantic, in a similar manner as whether a car that has just been filled up requires gas. If asked you could say "Yes, without it it will not run," or you could say "No, it already has plenty."

Walt

[baron]

What are we talking about, court evidence, where heresay and anecdote are allowed (more or less)? Surely the existence of ghosts is not something to be decided by court evidence.


Of course not. But this is what I'm talking about. Who said that evidence "decides" anything? Evidence is simply information that helps reach a conclusion. Why do so many people believe that evidence must be conclusive or else it's valueless?

A claim about the natural world is pretty much a scientific claim, wouldn't you say?

Not necessarily, in the way you mean. If the phenomenon of ghosts turns out to have a currently undiagnosed psychological explanation then classifying it as nonsense simply because no scientific evidence is available contributes nothing towards solving the issue. Indeed, it is contrary to the methodology of proper skeptical study.

Scientific evidence is not necessary in order to establish that there is something worthy of investigation. Anecdotal evidence is extremely valuable if studied sensibly, and in volume. Too many so-called skeptics (I'm not pointing a finger at you, merely stating in general terms) are lazy, content to sit there bleating "show me conclusive proof", instead of working to examine the evidence that does exist.

I'm not saying for a moment that all areas of the alleged paranormal hold potential for new discovery. Many are complete garbage. However, I came to that conclusion by studying the evidence available for each phenomenon, not by simply applying the thinking "no conclusive scientific evidence = a bunch of woo."

[Paul C. Anagnostopoulos]

Why do so many people believe that evidence must be conclusive or else it's valueless?
I don't know anyone who believes anything like that.


Not necessarily, in the way you mean. If the phenomenon of ghosts turns out to have a currently undiagnosed psychological explanation then classifying it as nonsense simply because no scientific evidence is available contributes nothing towards solving the issue.
Who said it was nonsense? ... Nope, the word nonsense only appears in your post.


Scientific evidence is not necessary in order to establish that there is something worthy of investigation.
Who said there was nothing worthy of investigation?


However, I came to that conclusion by studying the evidence available for each phenomenon, not by simply applying the thinking "no conclusive scientific evidence = a bunch of woo."
No one said that either.

Meanwhile, anecdotes are very weak evidence that contribute little to the investigation of a claim such as ghosts. If you are truly interested in whether ghosts exist, or in an alternative psychological explanation, then you have to treat it as a scientific question.

~~ Paul

[baron]

Meanwhile, anecdotes are very weak evidence that contribute little to the investigation of a claim such as ghosts. If you are truly interested in whether ghosts exist, or in an alternative psychological explanation, then you have to treat it as a scientific question.

You couldn't be more wrong. Without proper assessment of anecdotal evidence it's impossible to even guess where to begin scientific investigation.

[baron]

And with that, it's 2007. Woo hoo.

[Paul C. Anagnostopoulos]

You couldn't be more wrong. Without proper assessment of anecdotal evidence it's impossible to even guess where to begin scientific investigation.
Oh, I never said that anecdotal evidence can't be used to decide where to spend one's time, did I? It's perfectly fine for that sort of prioritizing. But it's still not evidence for the veracity of the claim in question.

But I was misleading when I said "... contribute little to the investigation of a claim ..." It can contribute to the direction of the investigation, just not to the conclusion.

On the other hand, how exactly do anecdotes about ghosts help us decide what to investigate? Can we tell from the anecdotes whether we should spend our time searching for ghosts or sending the claimants to psychologists? I think whichever way we go probably depends more on our presuppositions than on the content of the anecdotes.

Analysis of anecdotes is heavily theory-laden.

~~ Paul

[baron]

On the other hand, how exactly do anecdotes about ghosts help us decide what to investigate?

Well, I would suspect many people who are unfamiliar with the subject matter associate ghosts with some form of afterlife, and therefore would advocate scientific study in this area. I would say that this is not logical, being that the majority of reports of identifiable apparitions describe people who are still alive. This is just one example where up-front study of anecdotal evidence can prevent a bogus line of investigation.

[Paul C. Anagnostopoulos]

Well, I would suspect many people who are unfamiliar with the subject matter associate ghosts with some form of afterlife, and therefore would advocate scientific study in this area. I would say that this is not logical, being that the majority of reports of identifiable apparitions describe people who are still alive.
They do? I did not know that. But we still don't know whether to investigate ... what? ... projection of souls or the psychology of the claimants. Or how do we know the claimants aren't seeing a dead person whom they don't know, and so force-fitting the ghost's appearance to someone they do know? It's an apparition, after all.

I guess I have a hard time with a seemingly logical conclusion drawn from something so outrageous as apparitions of undefined entities (ghosts, souls, etc.).

~~ Paul

[Paul C. Anagnostopoulos]

Wikipedia, for what it's worth, says that most apparitions are unrecognized:

http://en.wikipedia.org/wiki/Hallucinations_in_the_sane

~~ Paul

[Beady]

I'm not convinced. This implies that mundane or only moderately interesting scientific claims can be answered with less-than-compelling evidence.

Yes, that's true.

You want to call someone on the phone but, before you can pick it up, the same person calls you. This is evidence that you were thinking of each other, something that is easy to accept with fairly low demands being placed on the evidence, but it is also evidence of a psychic event. If evidence is evidence, then there is no reason to place a higher demand on the evidence to prove the psychic event.

Once a claim is a scientific claim, evidence is evidence.


Paul, why don't you consider this an excluded-middle argument?

How about "Extraordinary claims require good old scientific evidence, but don't expect to get away easily."?

Ah yes. Much better than the original.

[Paul C. Anagnostopoulos]

You want to call someone on the phone but, before you can pick it up, the same person calls you. This is evidence that you were thinking of each other, something that is easy to accept with fairly low demands being placed on the evidence, but it is also evidence of a psychic event. If evidence is evidence, then there is no reason to place a higher demand on the evidence to prove the psychic event.
I agree, except that the evidence for "thinking of each other" and "making telephone calls" is already in. It's done, finished, agreed upon. Now if you go making the new claim that thoughts were projected between the two of you, there is no evidence for that. So it's time to collect the good old standard, ordinary, scientific evidence for telepathy.


Paul, why don't you consider this an excluded-middle argument?
I'm not sure what you're saying. There is court evidence and there is scientific evidence. If you can describe some kind of evidence between the two, I'd be happy to consider it.

~~ Paul

[billydkid]

Yes, that's true.

You want to call someone on the phone but, before you can pick it up, the same person calls you. This is evidence that you were thinking of each other, something that is easy to accept with fairly low demands being placed on the evidence, but it is also evidence of a psychic event. If evidence is evidence, then there is no reason to place a higher demand on the evidence to prove the psychic event.

Much better than the original.

I don't see how it is evidence of a psychic event.

[Beady]

There is court evidence and there is scientific evidence. If you can describe some kind of evidence between the two, I'd be happy to consider it.

Actually, Paul, you are the one being imprecise. You have made two apparently conflicting statements: "Evidence is evidence," and then you distinguish between legal and scientific evidence. Now, I agree with you completely on the latter point, but I think we can both agree that the legal sphere is not at all what we are talking about so it may be less confusing if it is not mentioned again.

Someone above (I can't find the post) is correct in that you are making a needless semantic distinction between evidence and the emphasis we place upon it. To return to my own example, no one would argue that a simultaneous mutual attempt at a phone call is evidence that two people were thinking of each other (I daresay it happens "all the time"), but a claim that it was a psychic connection that caused the attempt would (should) be met with demands for additional evidence. The exact same piece of evidence is sufficient to establish one claim but not the other; a rather ordinary claim is explained by a rather ordinary explanation. That two people share a psychic connection, however, if proven true, would rewrite science as we know it, not just adding to our knowledge but changing that knowledge we already possess. It would demand a far more stringent proof, one with far fewer possible loopholes. In likelyhood, the history books would say that scientists were put onto the scent by that phone call, but that extrordinary means were used to verify the suggestion.

So, you would have a phone call and a series of highly elaborate and sophisticated (and probably expensive) experiments, both serving as evidence of a psychic connection. I honestly fail to see any justification for saying that the call and the experiments are both evidence and therefore are equal in importance. If they have equal importance, then why not forget the experiments and just go with the phone call?

[Beady]

I don't see how it is evidence of a psychic event.

It's an example, for crying out loud. Work with me.

[Merko]

No, no, ALL scientific claims demand an extraordinary level of evidence.

I don't agree. For most branches of science, even fairly stringent experiments rely on assumptions that are not rigorously proven. Basically, if everyone agrees that something is 'trivially' true, no further evidence is usually presented. It is then open to anyone to challenge this assumption. As long as no one does, no effort is made to provide more evidence.

[Paul C. Anagnostopoulos]

Actually, Paul, you are the one being imprecise. You have made two apparently conflicting statements: "Evidence is evidence," and then you distinguish between legal and scientific evidence. Now, I agree with you completely on the latter point, but I think we can both agree that the legal sphere is not at all what we are talking about so it may be less confusing if it is not mentioned again.
I meant "scientific evidence is scientific evidence." I so blatantly dismiss court evidence as having anything to do with reality that I forget to clarify what I mean.


The exact same piece of evidence is sufficient to establish one claim but not the other; a rather ordinary claim is explained by a rather ordinary explanation. That two people share a psychic connection, however, if proven true, would rewrite science as we know it, not just adding to our knowledge but changing that knowledge we already possess.
The reason one would rewrite science and not the other is because the former (thinking about one another; making telephone calls) has already had its evidence presented and accepted. It's already rewritten science. Telepathy only requires "extraordinary" evidence because we've not seen any evidence for it at all. How about:

Unevidenced claims require some kind of damn evidence!


~~ Paul

[Paul C. Anagnostopoulos]

I don't agree. For most branches of science, even fairly stringent experiments rely on assumptions that are not rigorously proven. Basically, if everyone agrees that something is 'trivially' true, no further evidence is usually presented. It is then open to anyone to challenge this assumption. As long as no one does, no effort is made to provide more evidence.
Could you give an example of this?

~~ Paul

[drkitten]

On the other hand, how exactly do anecdotes about ghosts help us decide what to investigate? Can we tell from the anecdotes whether we should spend our time searching for ghosts or sending the claimants to psychologists?

Er, yes? Obviously?

As a simple example, the content of a ghost anecdote can give us a strong clue about whether or not it's worth examining; if it turns out to be (for example) a well-known stage illusion or a well-known effect (such as the ouija board and ideomotor effect), then there's not much there to investigate. We might decide to dismiss such "obvious trickery" as unworthy of investigation (especially if our time/resoures are limited) or we might decide to investigate such anecdotes first just to sweep away the detritus.

Similarly, the circumstances of the anecdotes can tell us much; several independent reportages of the same thing suggest that there's a real, physical phenomenon to investigate as opposed to a simple case of hallucination. If I see the archangel Gabriel in the sky above my house, I may simply be bonkers. But when people all over town are reporting the archangel Gabriel, it's probably a whole bunch of damn-fools who can't tell comets from archangels.

[drkitten]

Could you give an example of this?

Parity conservation?

[Beady]

Unevidenced claims require some kind of damn evidence!

Umm, Paul, is there any way I could dissuade you from public eloquence?