Just Coincidence?

[Ashles]

I've had dreams of people dying who didn't really die. Are we counting those kinds of dreams too, or only the ones that match actual deaths?

Well since we're pretending I guess you can count what you like, ignore what you like and guess at numbers whenever you fancy it. Then statistically manipulate the resulting random numbers.

Apparently its a useful way to learn more about the world.
I hear Einstein used the same method to formulate his Special Theory of Relativity.

 

[Thomas]

Well, again, thanks for all the responses, but again, no one has actually given me an answer to the question I have posed.

Yes, I am aware that an actual computation of the probability is not possible. Yes, I am aware of the limitations of asking people to remember such occurrances, that they are not likely to remember misses, etc.

But I am not asking for an assessment of the probability of such an occurrance. What I am asking is at what point do you stop considering coincidence to be a justifiable explanation and start examining other possibilities. This is known as setting the significance level for a test. It is generally recommended that this level be settled on prior to beginning a study.

Generally, for most experiments and studies, 95% is used. That is, you have a 5% chance of wrongly rejecting the null hypothesis - in this case, the null would be that such events are just coincidence.

Now, I agree with the idea that extraordinary claims require extraordinary evidence. JREF requires a 99.9% level of confidence for the preliminary test, and a 99.9999% level of confidence to win the million, equivalent to a 1 in a million chance it was just coincidence.

Assuming we had the ability to gather accurate data on the phenomena (I know, a BIG assumption but just pretend it could be done), what level of significance would be appropriate for rejecting the null hypothesis?

Beth

I personally don't know which tables the JREF find to be sufficient, but I think you're wrong in your assumption concerning the 99.9%. However, since your original question was what we would consider coincidental enough to go as a genuine paranormal phenomenon, then, well, I can only speak for myself here, but I would begin with a laws of chance table like this one:

http://www.automeasure.com/chance.html

Hmm.. For the dreams.. a thing that is essential to remember is, that it isn't necessarily just coincedence. Often dreams will bring things up that are close to reality. I have them all the time. Dreams are hardly trying to tell us anything, they are trying to balance our emotions by picking things from real life and connecting them in our dreams: How this balancing mechanism works in detail is the big question. One special theory I've heard from evolutionary psychology in this concern, is that dreams try deliberately to generate realistic scenarios, all, so we will stay sleeping and thus charge undisturbed for a brand new day. Hereby improving our survival and reproduction skills.

In cases where people dream that someone else has died, and then wake up to realize that it is true, then the first thing I would check for is; how likely that scenario was to occur in the first place. Was the person very old? Was the person an alcoholic or a drug abuser? Was the person already sick? A formula 1 driver? Mountain climber? etc. etc..

If it on the other hand is a very odd and/or rare scenario, then I would ask to see a similar scenario replicated. Then get the documentation for paranormal activity through several tests.

 

[Psi Baba]

I have two major problems with this whole idea.
1) Whether there is even a coincidence to begin with is questionable. Dreaming of someone dying and having them actually die soon afterward is only a concidence because the person who had the dream makes it one. The two events (the dream and the death) are intrinsically meaningless and any perceiveced connection between the two has no basis in reality. It's purely a perception.
2) Any attempt at a scientific study that involves dreams is automatically suspect. We only remember a fraction of the dreams we have (so we're told. How anyone could even know that, I'd like to know). If that's true, all we have to work with are the dreams that are remembered, an already adulterated sample. Then, there is no way to verify that what we "remember" is actually the dream we had. Everone knows that some dreams are recalled clearly and others vaguely. Still, verification is impossible. The dreams are not recorded. You can't test the dreamer's recollection against a reference copy. So any academic discussion involving dreams must, by nature, rely on pure anecdote. It is inescapable. This makes any and all analysis of dream content highly suspect and useless as data for serious scientific research.

The only way to get an answer to the question about statistical probability requiring an explanation beyond coincidence is to start with a subject that yields verifiable data. Dreams just don't cut it.

 

[Thomas]

2) Any attempt at a scientific study that involves dreams is automatically suspect. We only remember a fraction of the dreams we have (so we're told. How anyone could even know that, I'd like to know). If that's true, all we have to work with are the dreams that are remembered, an already adulterated sample. Then, there is no way to verify that what we "remember" is actually the dream we had. Everone knows that some dreams are recalled clearly and others vaguely. Still, verification is impossible. The dreams are not recorded. You can't test the dreamer's recollection against a reference copy. So any academic discussion involving dreams must, by nature, rely on pure anecdote. It is inescapable. This makes any and all analysis of dream content highly suspect and useless as data for serious scientific research.

The only way to get an answer to the question about statistical probability requiring an explanation beyond coincidence is to start with a subject that yields verifiable data. Dreams just don't cut it.

..but, in this case you can still test the claim. Place the claimant in a closed facility, and see how many times in a row the claimant can dream things he or she couldn't possibly know - news with accurate details etc. (my guess is that the count here would be quite low, but) it can be done.

 

[Beth]

I personally don't know which tables the JREF find to be sufficient, but I think you're wrong in your assumption concerning the 99.9%. However, since your original question was what we would consider coincidental enough to go as a genuine paranormal phenomenon, then, well, I can only speak for myself here, but I would begin with a laws of chance table like this one:

http://www.automeasure.com/chance.html


These are comprehensive tables listing probabilities from 0.1% to 90.0%. At what probability do you consider it reasonable to reject the hypothesis of coincidence?

Beth

 

[Beth]

I've had dreams of people dying who didn't really die. Are we counting those kinds of dreams too, or only the ones that match actual deaths?

Yes, if someone were to attempt such a study, such dreams would need to be counted.

Beth

 

[Beth]

Sorry I think you took this the wrong way.

I picked 8 as an entirely random figure between 0 and 100.

Still I'm pleased you took my random figure as statistically acceptable.

And I'm sorry to learn that you were not serious about it. I guess I am still without any answer to my question.

Not all theories are equally valid Beth, and it is downright silly to say so.

And when have I said that? The rest of your post seems to be nothing more substantial than personal insults, which does not add to your credibility in my opinion. Giving a specious answer to a serious question doesn't either.

Beth

 

[delphi_ote]

You'd have to know the frequency of dreaming about a death in the general population. I wouldn't even know where to start.

Paj, this seems like a simple enough experiment to me. Once one of our beloved psychics wins the JREF challenge, we'll just have them read a random population sample's dreams for a few nights to establish the frequency with which one person dreams about another dying. From there, it's just a matter of controlling for biasing variables (i.e. Do we dream about diseased people dying more than healthy ones?) Even the control experiments could make use of our "scientific psychics." If we could only reproduce psychic powers in a laboratory, we could solve this mystery with one elegant experiment.

Of course, if psychics weren't real this experiment would be impossible... but we all know what a ridiculous scenario that is!

 

[Bronze Dog]

Paj, this seems like a simple enough experiment to me. Once one of our beloved psychics wins the JREF challenge, we'll just have them read a random population sample's dreams for a few nights to establish the frequency with which one person dreams about another dying. From there, it's just a matter of controlling for biasing variables (i.e. Do we dream about diseased people dying more than healthy ones?) Even the control experiments could make use of our "scientific psychics." If we could only reproduce psychic powers in a laboratory, we could solve this mystery with one elegant experiment.

Of course, if psychics weren't real this experiment would be impossible... but we all know what a ridiculous scenario that is!

Seems to me it just might be possible if we can read minds by somehow watching the brain shuffle around its various chemicals, but I doubt there's a healthy way to do it in such detail.

 

[Thomas]

These are comprehensive tables listing probabilities from 0.1% to 90.0%. At what probability do you consider it reasonable to reject the hypothesis of coincidence?

At some of the probabilities, depending on the number of tries. Like the table and the example says. It states when you're inside the realm of probability, and when you're not. Of course this table can't ever be 100% clear of errors, but it's some of the best we can do - and something I would accept on hold.

 

[Ashles]

And I'm sorry to learn that you were not serious about it. I guess I am still without any answer to my question.

Because it cannot be sensibly answered at the moment.
I am confused as to how you think it could without randomly pulling figures out of the air. As I did.

And when have I said that? The rest of your post seems to be nothing more substantial than personal insults, which does not add to your credibility in my opinion. Giving a specious answer to a serious question doesn't either.

Hardly personal insults, merely disbelief that someone with your level of training could think that this sort of issue can be clarified with statistics.
We don't have good data, it is hard to see how we could even acquire good data, and yet you are bypassing all these stages and wondering what level of probability would be adequate to reject coincidence?
And again I ask why would usual scientific standards not be adequate?

It seems as though you are trying to put a highly dubious claim (can dreams predict real events) on some kind of legitimate footing by sggesting a statistical analysis.
But as it stands we can realistically no more sensibly do that than we can analyse reports of fairy spotting, or statistically calculate how likely the average person is to receive an alien implant.

Without good data the whole question is moot. Any figures provided by anyone will undoubtedly be fairly meaningless.

 

[Bronze Dog]

Little something I just remembered: My mother commonly has dreams of me and my brother getting in car accidents, and such. So far, those accidents haven't happened. She's just naturally a worrywort, and it seems to be reflected in her dreams. But if she happened to dream that before an accident, chances are, she'd remember the dream and probably confabulate some changes to the dream to fit it with reality (shoehorning). It's also possible she'd remember an earlier dream and thought she dreamt it the night before. (Cryptonesia[sp]) I've had occasions where some incident or perception reminds me of a dream from years ago.

 

[Thomas]

Ok, I have an idea how this could be tested. It's rather grotesque, so.. be aware..

One could ask a person who was sentenced to death, if he and his family would participate in an experiment for science.
He would get an extra 14 days to live and get executed on a random day in that period. Then his family are to guess on which day it happened from premonitions in their dreams when the 14 days has passed.

Well, this is quite grotesque as I said, but it's the only way I can imagine it done (in my sick-sick mind).

If people claim to have had dreams that predict the future in other regards, say, predicting great happenings, worthy of the news? One can isolate them from the news and see if they're right with just 1-2 tries a day.

The best way of course, is the Thomas Huts: Here you are locked in, inside a little hut with no electricity and where you can't stand up. You are only to come out when you have either predicted something very accurately, like the lottery number several times in a row, or, when you have admitted that the paranormal most likely is but baloney.

When my malicious empire - that I dreamt about last night - has come true, everybody are to be confined to a Thomas Hut sooner or later.
I know these are old fashion methods, but we are to take old fashion means to use against these ancient myths and fairytales

 

[Beth]

Re: Re: Just Coincidence?

In direct answer to your question, I would consider a paranormal explanation as a possibility when the probability of the paranormal effect was greater than the cumulative probability of the mundane effects, including selection bias, mismemory, or lying on the observer's part.

Unfortunately, since I consider the a priori probability of lying to be greater than the a priori probability of paranormal events, this really means that no amount of pure observational statistics will be able to achieve the required confidence level.

Thank you attempting a direct answer to my question, but you forgot to mention any actual numbers. I don't know what a priori probability you would assign to lying on the observers part, mismemory, etc., so I still don't know what probability you are thinking of.

At any rate, don't worry so much about the problems that arise when doing an actual study. This is a thought experiment. Think about it in more personal terms and presume that your memory/perception is accurate, you are not lying, and you are not ignoring any "misses". Now, how low does the probability of a coincidence have to be before you would consider other explanations?

Beth

 

[Dr Adequate]

My question: how low does the probability of a coincidence (or series of coincidences) need to be before you would be willing to consider a paranormal explanation as a possibility?

This is a bit of an odd question. I mean, it's always a possibility. I'd like someone to show that it's a probability, and then keep on adding nines after the decimal point until there's enough of them that it would just be a waste of money to test the hypothesis further. I guess when you get to 99.999% certain you can stop.

But how are you going to make such an assessment of probability?

To me they seem to happen far more frequently than mere random chance would imply, but it is quite difficult to assess the probability of such random occurrances.

Quite so. We were chatting to a YEC on another thread, who said that the number of fossils we see today is unlikely without a global flood. I asked him a couple of questions: how many fossils do we see today, and how many fossils would you expect to see if there'd been billions of years of sedimentation instead?

You see the parallel, I hope. You don't know how many prophetic dreams there actually are, you don't know how many there would be by chance --- but you're postulating a miracle to explain a difference between the two which you have not actually demonstrated.

 

[TheBoyPaj]

Well, since believers often say that their particular event "could not have happened by chance", I would expect zero probability of it occuring by normal means.

Test the actual claim, I say.

 

[drkitten]

Re: Re: Re: Just Coincidence?

At any rate, don't worry so much about the problems that arise when doing an actual study. This is a thought experiment. Think about it in more personal terms and presume that your memory/perception is accurate, you are not lying, and you are not ignoring any "misses". Now, how low does the probability of a coincidence have to be before you would consider other explanations?

If I am allowed to assume the blatantly false, then anything follows.

My working assumptions about the reliability of human memory or perception (supported by a lot of experiments) is that minor details of little causal effect are correct about half (50%) of the time. (No, this isn't an exaggeration. For example, Nickerson and Adams found that people could typically remember only about 3/8 of the details on a (US) penny.)

You can check it for yourself, if you like. I just pulled a US quarter out of my desk drawer. Can you answer the following questions?

• Is the edge milled or smooth?
• Does the date appear at the top or bottom of the coin?
• Does the date appear on the head or the tail?
• Does Washington's head face left or right?
• Which side of Washington's head has the motto?
• Is the eagle facing left or right?
• Does it say "quarter dollar" or "twenty-five cents"?
• Is the word "Liberty" written in all capitals or not?

Obviously, you can "cheat" and look at a quarter yourself. Or perhaps your memory is honestly good enough (or you are lucky enough) to answer all these questions accurately. But most people aren't that good.

And, in fact, most people not only aren't that good, but they don't even know they're not that good, and they will swear up and down that they are remembering correctly, until you pull a quarter out of your pocket and show them....

.... which explains part of my suspicions about reports of the paranormal.

 

[juryjone]

Re: Re: Re: Re: Just Coincidence?

You can check it for yourself, if you like. I just pulled a US quarter out of my desk drawer. Can you answer the following questions?

Would that be a regular quarter or a state quarter?

 

[Bronze Dog]

Re: Re: Re: Re: Re: Just Coincidence?

Would that be a regular quarter or a state quarter?

I'm guessing regular. Tested myself, and I got 6/8. Missed on the directions of Washington's and the eagle's heads.

 

[drkitten]

Re: Re: Re: Re: Re: Re: Just Coincidence?

I'm guessing regular. Tested myself, and I got 6/8. Missed on the directions of Washington's and the eagle's heads.

Thank you. (And, yes, it was a "regular" quarter.)

At the risk of beating a greasy spot on the ground where a dead horse used to be, I can thus infer (pending better evidence), that BronzeDog's memory for detail is "about" 75% accurate. (Well done, by the way). But this also establishes a baseline for his credibility. If he (she?) tells me something that I judge to be less than 25% likely to be true, I can justifiably chalk it up to the foibles of our all-too-human memory.