Extraordinary Claims Require Extraordinary Evidence

[Cyberman]

Let's see if a hypothetical might illustrate this.

Say you're walking home tonight across a muddy field and you see a trail of hoofprints. Nothing else is evident, no other sign or cause. What is the most plausible explanation?

A) Horse
B) Zebra
C) Unicorn

More importantly, what is the minimum standard of evidence you would accept for each of these?

[RoadRunner79]

Let's see if a hypothetical might illustrate this.

Say you're walking home tonight across a muddy field and you see a trail of hoofprints. Nothing else is evident, no other sign or cause. What is the most plausible explanation?

A) Horse
B) Zebra
C) Unicorn

More importantly, what is the minimum standard of evidence you would accept for each of these?

My assumption would be a horse (neither zebras nor unicorns are common in this area).  Beyond that, I would look to others for a more detailed evaluation. (is there even a difference between horse, zebra and unicorn hoof prints?) I would look at if they are knowledgeable on the subject, are there contrary views to be accounted for, and do they site and base their claim on the evidence.

The minimum standard of evidence would be sufficient to demonstrate the claim, and rule out the others.  I'm doubtful that your hoof prints would suffice.

[Whateverist]

Extraordinary Claims Require Extraordinary Evidence:

What an extraordinary thing to say.  I hope you can back that up.

[Esquilax]

My assumption would be a horse (neither zebras nor unicorns are common in this area).  Beyond that, I would look to others for a more detailed evaluation. (is there even a difference between horse, zebra and unicorn hoof prints?) I would look at if they are knowledgeable on the subject, are there contrary views to be accounted for, and do they site and base their claim on the evidence.

The minimum standard of evidence would be sufficient to demonstrate the claim, and rule out the others.  I'm doubtful that your hoof prints would suffice.

The point is that, were somebody to be with you and claim that a horse or zebra made those tracks, you would not need to first determine whether horses or zebras are possible. It's not an extraordinary claim because it is, itself, supported in some measure. With zebras there would be an additional set of criteria that would need to be fulfilled (are there zebras in the area? If not usually, how did one get here? etc) because that claim is slightly more extraordinary than the baseline experience of your standard western person.

When it comes to unicorns though, now there's a lot more work to do, because the existence of unicorns is not a given, nor are a series of other questions about their characteristics that would need to be asked before we could take the claim that they made hoof prints in this specific area of the world seriously. It is a claim for which none of the basic premises have been demonstrated, making it extraordinary in that it currently contravenes our understanding of the world, and you'd have extra legwork to do getting the claim demonstrated. Hell, even if we did literally find a horse with a horn making those tracks there would be additional investigation needed, both in terms of what was meant by "unicorn" in the original claim, and in terms of the nature of the creature, because they still might not line up right.

Like it or not, there is additional necessary evidence required for extraordinary claims versus mundane ones, because you can't just skip the baseline demonstration of possibility to get to a given conclusion, and you also can't just take a phenomenon as evidence of its cause: you would actually need to demonstrate that any given supernatural claim comes from an actual supernatural cause, and if you had evidence of that it would be extraordinary indeed, and would certainly require more work than regular evidence would.

[Angrboda]

If you're talking about science, you don't need this phrase at all. Any claim must make specific testable and falsifiable predictions. This is where anything to do with religion falls down instantly because it makes no such things.

Actually, different branches of science, say medicine and physics, may use different standards.

It comes back to what I was saying about the statistics of type I and type II errors. Extraordinary claim means one where there is no plausible mechanism of action, or none at all. For example, ESP. Extraordinary evidence is quantified in terms of the statistical likelihood of getting the same results by chance instead of cause and effect. For ESP, you would use tighter standards.

[Cyberman]

My assumption would be a horse (neither zebras nor unicorns are common in this area).  Beyond that, I would look to others for a more detailed evaluation. (is there even a difference between horse, zebra and unicorn hoof prints?) I would look at if they are knowledgeable on the subject, are there contrary views to be accounted for, and do they site and base their claim on the evidence.

The minimum standard of evidence would be sufficient to demonstrate the claim, and rule out the others.  I'm doubtful that your hoof prints would suffice.

In other words, your default assumption would be to the mundane explanations first until more extraordinary ones can be demonstrated. Moreover, you recognise that those extraordinary options require stronger evidence. That's all ECREE means.

[RoadRunner79]

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The point is that, were somebody to be with you and claim that a horse or zebra made those tracks, you would not need to first determine whether horses or zebras are possible. It's not an extraordinary claim because it is, itself, supported in some measure. With zebras there would be an additional set of criteria that would need to be fulfilled (are there zebras in the area? If not usually, how did one get here? etc) because that claim is slightly more extraordinary than the baseline experience of your standard western person.

When it comes to unicorns though, now there's a lot more work to do, because the existence of unicorns is not a given, nor are a series of other questions about their characteristics that would need to be asked before we could take the claim that they made hoof prints in this specific area of the world seriously. It is a claim for which none of the basic premises have been demonstrated, making it extraordinary in that it currently contravenes our understanding of the world, and you'd have extra legwork to do getting the claim demonstrated. Hell, even if we did literally find a horse with a horn making those tracks there would be additional investigation needed, both in terms of what was meant by "unicorn" in the original claim, and in terms of the nature of the creature, because they still might not line up right.

Like it or not, there is additional necessary evidence required for extraordinary claims versus mundane ones, because you can't just skip the baseline demonstration of possibility to get to a given conclusion, and you also can't just take a phenomenon as evidence of its cause: you would actually need to demonstrate that any given supernatural claim comes from an actual supernatural cause, and if you had evidence of that it would be extraordinary indeed, and would certainly require more work than regular evidence would.

---

I suppose that is where I differ. If the evidence points to a zebra making the prints and eliminates a horse or other animal. I am going to consider that evidence to indicate a zebra is in the area and making those prints (even if a zebra cannot be shown to be in the area). I'm not going to require additional evidence to make that proclamation. Although I may question a single point of evidence in general (we could be mistaken on a single instance, but multiple points of evidence pointing to the same thing is less likely to be in error).

In the case of a unicorn, I am likely going to (similar to yourself), ask how they know it is a unicorn and what they are basing their claims on. And again I am going to look for multiple sources of confirmation. In the case of a horse or zebra, I may be more likely to assume the person knows what they are talking about (given credentials or seeming to be knowledgeable on the subject). It's not that less evidence is required in one instance over the other, rather; I am more willing to make assumptions, and take things on faith.

[robvalue]

Jorm: Sure, you're right, statistical analysis would be a little different. It's never possible anyway to prove a theory correct with 100% certainty, only that it appears true beyond reasonable doubt.

In the case of ESP and bullshit like that, the claim would be something like the probability of guessing which card the person is holding is higher than just guessing. I agree it's not the same as making a specific prediction. Good point!

It still has to be testable and falsifiable though, although the parameters for success have to be carefully chosen like you say.

RR: Can you give us one single example to indicate what the point of this thread is? Because I still don't get it.

Are you saying if several people said they saw a unicorn, you'd believe them?

[GrandizerII]

And again I am going to look for multiple sources of confirmation.

Depends on the quality of the sources as well. Multiple sources "confirm" that people have been kidnapped by extraterrestrial aliens. But so what? Doesn't make it likely true.

[robvalue]

Indeed. There's a reason science doesn't accept anecdotal evidence, which is that it's shit.

If you're proposing that science should start accepting it, then I'm afraid that's a dead end.