[anonymous]

Originally Posted by eyemsougly

it sounds like the big flaw was using VHS tapes, which was pretty much all that was available back then. As the tapes get worn down subjects might beinadvertantly cued that a certain segment was the target. Apparently there being more hits in later parts of trials gave weight to this or something.

Hopefully this link works: Ganzfeld Experiment


Anyway, since 2000 everything has been computerized. Unfortunately the article doesn't specify how true to the ganzfeld protocol the 20 post-2000 studies have been so the results might not be as bad as they seem on the surface.

According to "The Conscious Universe" published 1997, in chapter 13, p220 says this:

In fact, as we saw in chapter 5, the ganzfeld system at the University of Edinburgh used two separate video players to address this criticism, and successful effects virtually identical to those Honorton had reported earlier were still observed. Again, the implication of the criticism is that the ganzfeld results are explainable by this potential flaw, and it is not true.

Dean Radin has responded to some of the more recent criticisms on his blog:

http://deanradin.blogspot.com/2006/0...44514367222267

The post on the ganzfeld experiments that you mention by Andrew Endersby is quite comprehensive. He concludes that “... anyone who asserts that the ganzfeld has been proven by scientific standards is wrong. The field's reliance on incomplete meta-analyses seems to be cause for concern.”

However, if we assume that the “true” hit rate is the average of the 28.6% and 28.9% figures he cites, or 28.75%, and that the total number of ganzfeld-like studies is 6,700 as he cites, then the associated z = 7.09, p = 6.8E-13. This is equivalent to odds againg chance above a trillion to 1. And the funnel plot he presents rules out any obvious filedrawer effect. There is insufficient information in the article to gauge whether variations in experimental quality might be a problem, but I suspect that it wouldn't eradicate the very significant overall effect.

http://deanradin.blogspot.com/2006/0...82249701338264

The ganzfeld MA in Entangled Minds follows up on a more uniform circumscription (i.e. definition) for what constitutes the ganzfeld method. Endersby included any experiment conceivably related to the ganzfeld, whereas the published ganzfeld MAs have considered only those with hit/miss scoring. The circumscription is important because you could create a MA for any telepathy study ever conducted, and that could include perhaps millions of trials, because there were many ESP card tests conducted as telepathy tests. So where do you draw the line on what you're going to include? That's the purpose of creating a circumscription, to limit the scope of what you're studying. In any case, as I noted above, even with Endersby's database (which hasn't been independently checked as far as I know) you end up with an unambiguously non-chance effect.

http://deanradin.blogspot.com/2007/0...66483003109667

After listening to the Skeptiko interview, it reconfirms how I responded to Alcock's assertions in Entangled Minds (because his arguments in the interview are basically the same as those I wrote about in the book).

Each critique can be answered with, I believe, a reasonable counterargument. I won't bother to repeat them here.

One thing I disagree with that Alcock claims to strongly believe is that if parapsychology could provide clear evidence of a psi effect, then academic psychologists would trample each other to try to replicate these effects. And yet after Bem and Honorton's 1994 Psychological Bulletin article provided such evidence to the psychological mainstream, the response by academic psychologists was deafeningly silent.

So Alcock's view of how academia would respond to intriguing data is almost dead wrong.

I say "almost" because a recent study published in The Humanistic Psychologist does report a series of ganzfeld telepathy experiments by psychologists at Notre Dame. The article was "Finding and Correcting Flawed Research Literatures” by Delgado-Romero and Howard (2005, 33 (4), 293–303)."

Briefly, they conducted a series of eight new ganzfeld experiments. Their experiments resulted in a significantly positive overall hit rate of 32%, which is exactly the same hit rate found in a meta-analysis of 88 experiments consisting of 3,145 ganzfeld trials conducted from 1974 to 2004, as I report in EM.

Then amazingly, they explained their own successful results away by conducting a single follow-up experiment based on an ad hoc "psychic theory" they came up with, which resulted in a significantly negative hit rate!

So while psychologists weren't trampling each other to try to repeat the ganzfeld studies, there was at least one admittedly skeptical group at Notre Dame who did publish a replication, and it was successful. Somehow no one (including Alcock) paid attention to this.

I know of at least one other mainstream academic group that also tried to replicate the ganzfeld experiment, and it too was successful. But they've not yet published their results.