Tried to compute and this is what I got for the probability of getting *exactly one* correctly:

P(getting it right in one group) * P(getting it wrong in the other group) * P(getting it wrong it the last group) * 3 ways

= [1/12 * (1 - 1/12) * 1 - 1/12) ] * 3 = 21%

It’s a binomial probability with n=3, k=1, p=1/12

The chances of getting *at least one* correctly is indeed 23%.

It is puzzling to contemplate your calculation of the odds involving “accurately picking all three missing kidneys” [your words]. Actually, the numbers you showed represent a calculation of the composite probability of picking, PURELY BY CHANCE ALONE, the three correct patients along with the true location of the intact kidney in each (1/12 x 1/12 x 1/12) or P = 0.00058. Stated another way, the odds AGAINST a psychic (or anybody else) simply guessing the identities of all three patients and their kidney sites would be enormous (1728 to 1) in the absence of properly functioning woo. Thus, her confidently predicted complete success (3 correct patients, 3 correct sides) would have been hugely impressive, absent any trickeration or cheating on her part, since chance alone would have been an extremely improbable rationale for such an outcome. As I understand “woo-busting” this is the standard modus operandi that you folks use. It is perfectly fair.

What then could you have meant by writing that the “….odds of accurately picking the three kidneys” would be 1/1728…? Language is powerful when talking about probabilities and odds derived therefrom. Obviously, the use of “accurately” could not conceivably have referenced the woo per se. There was no way to calculate, or even estimate, the diagnostic accuracy of the woo up front–although we know it now from your carefully structured experiment. And it’s really lousy accuracy.

In sum, the verbiage “accurately picking” was misleading, because of the adverb “accurately”. What am I missing here? I think you meant to say “the odds of accurately picking all three patient/side pairs, by simple guesswork alone, would have been 1 to 1728″. Equivalently, absent any woo the probability of failing to just guess correctly all three patient/side pairs would be 0.99942.

Thanks. Amusing study. Good science. Bottom Line: Woo detection of missing kidneys = BS. See a competent professional if you think you might be missing an organ. I do think that the comment about her needing to see a psychiatrist was a cheap, ad hominem shot that detracts from the otherwise air-tight refutation of her woo.

I have been approached by several woos who try to coerce me into accusations against the IIG of cheating, meanwhile I assure them that the test was carried out correctly and that I failed all on my own.

Mark Edward is one of the most wonderful people I have ever met, he was always at hand at the test for me to share my thoughts with, and knowing Skeptics such as him assures me that Skeptics aren’t resentful of woos simply for what we are or what we might experience, but that it is the immoral, harmful and careless actions of woos that we need to stop.

So, stop it.

“One thing I really liked was her intense “psychic” concentration. This was eventually followed by a sort of slight nod to herself, as if some other part of her was agreeing with a voice in her head that was guiding her. We can see a wide spectrum of this kind of “duel personality” syndrome from those of us who may occasionally mumble or talk to ourselves while doing mundane activities to the street person who carries on long conversations with an imaginary person. I’m not sure where exactly Anita fits into this spectrum, but it was an interseting affectation. This was usually an affirmative nod and I never saw a “no” response from her. If she’s deluded, it’s a deep form of self-hypnosis or psychosis. As I watched her it was hard to see any signs of outright charlatanism.”

While I was feeling into the subjects, when ever a perception formed that was very clear and conclusive, I would nod to myself in affirmation as I received a perception that had formed to completion. The perceptions form based on something that I feel, and they gradually build up. I found great variety among the subjects, in that the perceptions from some built quickly and to completion, whereas from other subjects they grew slowly and not always to completion. Some subjects were harder to read and formed only incomplete perceptions, others were repeatedly very easy.

I would nod once I managed to form a perception to completion, whether it be of the kidney being present or it being missing, but clearly so. You did not see a nod for “no”, as I was simply observing what was taking shape within my mind.

It did require intense concentration, but there was no internal dialogue nor a separate voice in my head to guide me. I was simply observing the felt shapes as they appear, none different than when we lean closer to listen carefully and then nod when we think we hear. Everybody does this when we sharpen our senses, and such focus and nodding do not indicate mental anomaly.

It is none more self-hypnosis or psychosis than what is synesthesia, the experience of synthetic sensory perceptions that are based on something that was perceived from outside and is then further processed, and converted, into something entirely different.

Thank you Mark for an excellent article, and thank you so much for being there at our test.

VFF