Psychic prediction of mass graves turns out false

[tackattack]

The thing is that there is no evidence that there is anything at all to ESP.... Every time ESP has been put to the test in double-blind, controlled conditions, it fails miserably and any guesses fare no better than chance.

Did you not read the abstract.

In several experiments perceptual defensiveness as measured by the Defense Mechanism Test (DMT) has been found a useful tool to predict performance in extrasensory perception (ESP) tasks. Subjects with weak perceptual defensiveness have tended to obtain more hits in ESP tests than did subjects with strong defenses. Ten double-blind experiments involving a total of 462 subjects were conducted to test the replicability of the DMT-ESP relationship. Results of 2 of the experiments were independently significant. Meta-analysis of the 10 experiments yielded a significant relationship (z = 2.61, P = 0.0045). Meta-analysis of all 16 DMT-ESP experiments conducted so far revealed highly significant results (z = 3.87, P = 0.00006).

[lilphil1989]

http://www.sciencedirect.com/science/art...699290024J

Table 3 should tell you all you need to know about ESP.

I would also be a little worried about Table 2. The magnitudes of the Spearman's correlation coefficents are consistently low, whilst at the same time, they claim a very small P-value. This suggests an error in the statistical analysis or an unreasonable null hypothesis.
Unfortunately, the ESP literature seems to be plagued with misunderstanding, misuse, and in some cases even outright abuse of statistical methods.

ESP studies are also notorious for being exercises in confirmation bias. Positive results are submitted for publication, whereas negative results are ignored. The correct scientific thing to do is to report ALL of your results.
Although it has to be said that ESP researchers are not the only guilty parties in this respect, not by a long shot. Pharmaceutical companies do it all the time. It's considered research fraud to cherry-pick data from a drug trial and submit it for publication, so what they do is run many simultaneous trials, and only report on the few that happen to paint the drug in the best possible light.

[tackattack]

I wasn't using it to validate ESP phil. I don't have access to that particular studies statistical analysis, nor would I enjoy analyzing that (but I'm sure you would). I was using that one partiicular study (I'm sure there are more, it was just a simple google high hitter) to support my assertion that statistiacally there is not zero evidence that ESP breaks probablity. That alone invalidates a materialistic 5 senses is all we need world view. It is a study that is also directly a counter to DT's comment "no evidence that there is anything at all to ESP" . I feel there is something more than the strict materialist 5 senses view. If that view were valid, studies like this wouldn't be possible.

[lilphil1989]

I was using that one partiicular study (I'm sure there are more, it was just a simple google high hitter) to support my assertion that statistiacally there is not zero evidence that ESP breaks probablity.

How can you possibly use one study to demonstrate something statistically?

If that view were valid, studies like this wouldn't be possible.

Of course they would, that's the point I was making in my last paragraph about confirmation bias.

Imagine some normally distributed random variable, X, with mean <X> = 0. Now suppose that this underlying distribution is unknown to me, and I make the hypothesis that <X> > 0.
Now suppose that I make 100 trials, each consisting of 100 measurements of X, which correspong to one measurement of <X>. Given that X has mean 0, on average I will find that <X> > 0 50 times and <X> < 0 50 times.
Now suppose I say "aha! 50 successful trials!" and submit the results of those 50 trials for publication in the The International Journal of X Studies. Could that be considered evidence in favour of the hypothesis <X> > 0 ?

[tackattack]

No it couldn't support <X> > 0 . They could support the statement that X does not always equal 0... which was in essence the side of the strict materialists make.. that there is only 0 and nothing outside <X> = 0 which I think is false. Phil man I love to see you're awesome posts and love it when you and syn get into statistical conversations and math is flying everywhere.. but after a long night of caffine deprovation, CSS & Jquery, moderating, theological debates, my job, planning strategies and reading; your math concepts hurt my brain.

[Doubting Thomas]

You're forgetting, Tack, that positive scientific results have to be repeatable, which ESP tests never appear to be. You may get lucky and guess 50 cards in a row out of 100, but no so-called psychics ever appear to be able to do it reliably. So if you get one study which shows that someone may have a better than chance ability to guess something, unless they can do it again and again every time it's tested, it's not scientific and not a valid result.

That's why a psychic may get lucky and win the lottery once, but it's doubtful they could predict the winning numbers every day. If someone could do this, I guarantee they'd be playing the lottery. I know I would.

[tackattack]

There are plenty of studies.. I quoted one because posting walls of links really is in poor taste and difficult to manage if I heap all the info in one post. This was just a top result in the google search.
... why are they allowed to break the barrier of probability at all? I'll phrase it better; I see all the extra senses as underdeveloped muscles. Doesn't your sense of balance get better as you use it? Why not your sight? Your sight is your sight, how well you use it may change but you can't will your eyes from 40/80 to 20/20. They have a measurable maximum level and then we adapt the use of them better. If we use our primary 5 senses 96% (made up statistic) of the time and socially discourage the use of any other sense would it ever be able to develop naturally?

[lilphil1989]

There are plenty of studies..

Which are not repeatable, and often only publish the results that seem to support the hypothesis, thus suffering from confirmation bias.

why are they allowed to break the barrier of probability at all?

I think you misunderstand what it means for something to work no better than chance. It doesn't mean that the result of, say, guessing the outcome of 10 fair coin tosses, should be 5 correct and 5 incorrect every single time. It means that should be the average result. Sometimes a person may guess 10 correct, sometimes all 10 incorrect.

If you just ignore negative results, then it will look as though there's a real effect when there isn't.

[tackattack]

And you have a point about denying the negative results phil. It would emphasize/amplify the effect quite a bit. How do you know they're only publishing positive results? Was there a fault in the methodology of the experiment to allow for that? How do you know the results are unrepeatable? If you have, IDK, 20 or so studies, all with valid and different methodology coming to the same conclusion is that enough to get past reliability and confirmation bias? What number would be sufficient?

[lilphil1989]

And you have a point about denying the negative results phil. It would emphasize/amplify the effect quite a bit.

That implies there's an effect to amplify.

How do you know they're only publishing positive results?

Often it's right there in the paper. The author will come up with some hogwash about ESP not being "perfect", and then go on to use that to justify the dismissal of negative results. Of course this is terrible science, which is one of the reasons that ESP papers very rarely (if ever!) appear in a journal with any kind of decent reputation.