What Is The Statistical Probability That All Sightings Are False?

[Guest]

. . . impossible to prove something does not exist. My point is that since that is the case, someone who cannot prove bigfoot does not exist is acting on nothing more than their own belief system when they maintain that all reports can be false.

I see what you mean: Although all reports can be false because any one of them can be false, by the same token all reports can be authentic because any one of them can be authentic. You are charging that a skeptic chooses the former to actually be the case even though the latter might be the case.

I guess I'd counter that by using this logic we act on such belief systems all the time when we maintain that reports of unicorns, leprechauns, etc. are also false. I'm OK with that.

The real difficulty though is that I still think you're overestimating the weight that anecdotal accounts have in the opinions of skeptics about bigfoot (or unicorns or leprechauns or whatever). I am right now convinced that there is no bigfoot because there . . . is no bigfoot. Show me a bigfoot and I'll be convinced that there is a bigfoot. Anecdotal accounts don't factor much into my conviction that there is no bigfoot. If anything, they're the most interesting aspect of this phenomenon suggesting that there might be. But it's not any statistical phenomenon that can be invoked that makes anecdotes interesting, it's the anecdotes themselves: there are certain accounts for which the "I don't know" explanation is the only one that makes sense.

[indiefoot]

The difference between Bigfoot and unicorns, leprechauns, etc. is that to my knowledge no one with appropriate credentials has come out in favor of their likely existence. Still, you have no problem lumping them all together?

In order to pull this off you have to dismiss every report, every footprint, every hair, every toenail, etc.

Do you really believe there is no bias at work?

[Guest]

I'm no scientist ..... But I'm 99.9% sure to myself that there's nothing out there. Have yet to see anything that says: ewwwwwwww!!! That's real... Or that!! Sounds like nothing I have heard b4... The only thing that has ever made me think... Was the footage of a supposed Bigfoot walking up a snowy ridge.... Which the video was very limited.... Shocker!

[Guest]

. . . to my knowledge no one with appropriate credentials has come out in favor of their likely existence.

I have the appropriate credentials, and I've considered the same evidence as the people you might be thinking of. Appeals to authority don't make bigfoot real. Only a real bigfoot makes bigfoot real.

[indiefoot]

Sas,

You really place Bigfoot on the same level as unicorns and leprechans?

you can suggest whatever likelihood you wish based on your beliefs, but you cannot say that it's a statistical probability... not if you care about being accurate.

What proof would you offer that there is a higher probability that all reports are false than that not all report are false? Your opinion weighs the same as the next guys on the balance scales. So I'll stand behind my even odds.

[Guest parnassus]

JDL wrote:

Actually, skeptics are generally forthcoming in that they say it is impossible to prove something does not exist. My point is that since that is the case, someone who cannot prove bigfoot does not exist is acting on nothing more than their own belief system when they maintain that all reports can be false.

It's not just a belief system. We are talking about probability. :

How many reports have been proven true? zero out of many thousands. (and you would have to agree, I think, that many have been proven false).

So the possibility still exists that all can be false. According to probability theory, that possibility becomes larger with every false report. Again, you can believe whatever you wish, you can talk in layman's terms about likelihoods of this or that. but you shouldn't confuse your belief with probabiilty in the numerical sense of the word. That is what causes much of the confusion. The OP was about "statistical probability."

The other part of the confusion comes about because of a lack of understanding of probability theory: To restate what I have said a number of times, you cannot assume a probability and then do the (1-p)^n thing. It doesn't apply in this setting, because you don't know p; this is not dice rolling, or shooting baskets, or flipping coins. Evidential probability theory applies, and says regardless of the probability you start off believing, as each trial is negative, the chance that all will be negative, increases.

Incidentally, when I watch Finding Bigfoot town hall meetings, I see numerous little children claiming to have seen bigfoot. What do you think of the likelihood that they are telling the truth? why do you think they are raising their hands?

p.

Edited February 27, 2012 by parnassus

[JDL]

I see what you mean: Although all reports can be false because any one of them can be false, by the same token all reports can be authentic because any one of them can be authentic. You are charging that a skeptic chooses the former to actually be the case even though the latter might be the case.

I guess I'd counter that by using this logic we act on such belief systems all the time when we maintain that reports of unicorns, leprechauns, etc. are also false. I'm OK with that.

The real difficulty though is that I still think you're overestimating the weight that anecdotal accounts have in the opinions of skeptics about bigfoot (or unicorns or leprechauns or whatever). I am right now convinced that there is no bigfoot because there . . . is no bigfoot. Show me a bigfoot and I'll be convinced that there is a bigfoot. Anecdotal accounts don't factor much into my conviction that there is no bigfoot. If anything, they're the most interesting aspect of this phenomenon suggesting that there might be. But it's not any statistical phenomenon that can be invoked that makes anecdotes interesting, it's the anecdotes themselves: there are certain accounts for which the "I don't know" explanation is the only one that makes sense.

Saskeptic,

We've got more in common than not. I am still very critical of most information, particularly photos and video. For example, the photo revealed last week of the greying bigfoot with sparse hair and visible skin is unconvincing to me. I can't say that it isn't faked and I'm not ready to accept it at face value for a half dozen reasons. There's a lot of other evidence that I do not embrace.

Having had an encounter, though, I'm more judicious when it comes to reports. Since I know bigfoot to be real, I evaluate reports from that understanding. I still throw a lot in the dumpster. Most of the ones I do accept provide little information to get excited over. Just a date and location one can put into a database. Vanilla. It is a rare report that contributes some new, yet consistent, behavior or other observation.

Information regarding bigfoot is just like any other information I have to evaluate on a regular basis. Is the information possible, consistent? Does it add value? What is the quality of its source? How do I verify it? And so on.

Ultimately the perceived value of information comes down to one's own experience and judgement. I think we differ more in our experiences regarding bigfoot than in our judgement.

Parn,

Probabilistic analyses are based on assumptions. The assumptions are based on beliefs.

Edited February 27, 2012 by JDL

[Guest]

I think Unicorns & Leprechauns are actually more believable....

[Guest RayG]

You really place Bigfoot on the same level as unicorns and leprechans?

A couple hundred years ago maybe, but these days I think bigfoot is more like ghosts or UFOs.

RayG

[Guest]

Insert Ivory Billed Woodpecker for bigfoot, and study the differing response. Granted Ivory Bills did exist, but one sighting would not cause funding to be appropriated for a search. Ten thousand sightings might be a completely different story.

I can guarantee that if there was a legitimate Ivory-billed Woodpecker sighting by an ornithologist, or even video or a good picture of it, I could start booking my retirement. As it is our lab was fully funded for about 2 years because of a few questionable sightings. There is another lab in our building that is still funded.

http://www.fws.gov/ivorybill/pdf/IBWRecoveryPlan2010.pdf

This report is just the preliminary, if we would publish all the data we have generated since, it would be an order of magnitude longer in length.

Lance

Hmmm, now if bigfoot is proven to exist, I an really curious how much money would be put aside for research. Now keep in mind, When this Ivory-billed study group for formed, on the government side there was no windfall of money, most of it was shifted from other projects, and in this economy the same would happen if bigfoot is proven.

[Incorrigible1]

I think Unicorns & Leprechauns are actually more believable....

Just curious what it is that draws you to the BFF, in that case.

[indiefoot]

Ray, I don't know diddly about either ghosts or ufo's, your comparison of the phenomenon might be warranted. I think the comments about unicorns and leprechans are demeaning to the forum and it's members. That's just my opinion of course.

[Guest]

Just curious what it is that draws you to the BFF, in that case.

Sorry, I was being sarcastic. I am here because I want to believe.

[Incorrigible1]

Interesting, as your "I think Unicorns & Leprechauns are actually more believable...." sounded quite committal.

[Guest wild eyed willy]

+1 INC