The Ganzfeld Experiments

[amherst]

Since the accumulated data from the ganzfeld studies are, as H.J. Irwin writes in his Introduction to Parapsychology, "...increasingly being cited as scientific testimony not only for the ganzfeld effect but for the existence of psi itself," the question as to whether or not the evidence is valid should be of some importance to both the believers and skeptics who frequent this board. Therefore, I believe a detailed discussion of these experiments is needed. If you agree, then please familiarize yourself with the articles I've listed below. I look forward to an informed and fruitful debate.

amherst

http://comp9.psych.cornell.edu/dbem/ganzfeld.html

http://comp9.psych.cornell.edu/dbem/does_psi_exist.html

http://comp9.psych.cornell.edu/dbem/response_to_hyman.html

http://comp9.psych.cornell.edu/dbem/updating_the_ganzfeld_data.html

 

[DaveW]

It is my belief that the data presented is hardly significant. In fact, looking at Bem's own description of the tests and the following links, it looks like the vagueness of the accepted replies and allowed descriptions give them a decent shot at a better than chance result:

http://skepdic.com/ganzfeld.html

http://www.straightdope.com/mailbag/mganzfeld.html

Note: My statistics is a bit spotty, but it doesn't seem necessarily true that 32% is very statistically significant. I only skimmed the articles, but there didn't seem to be any mention of the actual number of data points, just repeated mentions of 28 tests.

 

[amherst]

It is my belief that the data presented is hardly significant. In fact, looking at Bem's own description of the tests and the following links, it looks like the vagueness of the accepted replies and allowed descriptions give them a decent shot at a better than chance result:

http://skepdic.com/ganzfeld.html

http://www.straightdope.com/mailbag/mganzfeld.html

How exactly would giving a vague description of a target give a subject "a decent shot at a better than chance result"?

Note: My statistics is a bit spotty, but it doesn't seem necessarily true that 32% is very statistically significant. I only skimmed the articles, but there didn't seem to be any mention of the actual number of data points, just repeated mentions of 28 tests.

A 1997 meta-analysis of the 2,549 ganzfeld sessions which had been reported up to that time revealed an average hit rate of 32.2 percent. The odds against this happening by chance are "...beyond a million billion to one"(Radin, 97). Most informed skeptics do not believe chance to be a factor.

amherst

 

[DaveW]

How exactly would giving a vague description of a target give a subject "a decent shot at a better than chance result"?

Hmm, maybe you didn't read Bem's own description of the test (or maybe I misunderstood it, but I don't think so) where he stated receivers had 30 minutes to respond... and based on the nature of the one response given, they were allowed to ramble... then their ramblings were judged. Bem even stated that they only had 4 things to receive, and insinuated that the receivers even knew what they were since they had a 25% chance (from his paper).

A 1997 meta-analysis of the 2,549 ganzfeld sessions which had been reported up to that time revealed an average hit rate of 32.2 percent. The odds against this happening by chance are "...beyond a million billion to one"(Radin, 97). Most informed skeptics do not believe chance to be a factor.

amherst

"most informed skeptics? OK, if you would be so kind as to share a few (links preferred)... like I said, my statistics are a bit spotty, maybe someone else can confirm the "million billion to one"? (Of course, you are assuming a 1 in 4 chance, which I don't think really existed because of the methodology).

 

[amherst]

Hmm, maybe you didn't read Bem's own description of the test (or maybe I misunderstood it, but I don't think so) where he stated receivers had 30 minutes to respond... and based on the nature of the one response given, they were allowed to ramble... then their ramblings were judged. Bem even stated that they only had 4 things to receive, and insinuated that the receivers even knew what they were since they had a 25% chance (from his paper).

In your original response to me, you seemed to claim that rambling subjects would be likely to get spurious hits. If that's true, and I'm not misunderstanding you, then explain how that could occur.

Further, the ganzfeld isn't "forced choice", as you seem to think it is, but "free-response". The difference being that in a free-response test the subject doesn't know what any of the potential targets are untill after the sending phase is finished. If you would take the time to carefully read even just the first article I listed in my original post, you would know this.

"most informed skeptics? OK, if you would be so kind as to share a few (links preferred)... like I said, my statistics are a bit spotty, maybe someone else can confirm the "million billion to one"? (Of course, you are assuming a 1 in 4 chance, which I don't think really existed because of the methodology).

"Today informed skeptics no longer claim that the outcomes of psi experiments are due to mere chance because we know that some parapsychological effects are, to use skeptical psychologist Ray Hyman's words, "astronomically significant."(Radin, 97)

amherst

 

[Ersby]

In your original response to me, you seemed to claim that rambling subjects would be likely to get spurious hits. If that's true, and I'm not misunderstanding you, then explain how that could occur.

Further, the ganzfeld isn't "forced choice" as you seem to think it is, but "free-response". The difference being that in a free-response test the subject doesn't know what any of the potential targets are untill after the sending phase is finished. If you would take the time to carefully read even just the first article I listed in my original post, you would know this.



"Today informed skeptics no longer claim that the outcomes of psi experiments are due to mere chance because we know that some parapsychological effects are, to use skeptical psychologist Ray Hyman's words, "astronomically significant."(Radin, 97)

amherst

It has been noted that longer responses get a gretaer hit rate than those which a curt and short. I don't know why.

And sometimes, the subject would know the nature of the target, be it photo from National Geographic or a phsyical location.

Who carried out the 1997 meta-analysis you mentioned?

 

[DaveW]

In your original response to me, you seemed to claim that rambling subjects would be likely to get spurious hits. If that's true, and I'm not misunderstanding you, then explain how that could occur.

I see you failed to read my amplifying links, so here is an excerpt:

The Ganzfeld is set up so that an interpretation must be made of a verbal report from the test subject to be matched against an image allegedly sent telepathically to the subject. Thus, even if an image bears little or no resemblance to the verbal description, if it is selected as the one most closely resembling the image verbally described, then it counts as a hit. For example, here is a verbal description taken from Dr. Berger's website on the ganzfeld:

I see the Lincoln Memorial...
And Abraham Lincoln sitting there... It's
the 4th of July... All kinds of fireworks...
Now I'm at Valley Forge... There are
fireworks... And I think of bombs
bursting in the air... And Francis Scott
Key... And Charleston...

There are quite a few images that would "match" this description, since the description itself contains at least eight distinct images (the Lincoln memorial, Lincoln, 4th of July, fireworks, Valley Forge, bombs, Francis Scott Key, Charleston) to which one could easily add a couple more, such as the American flag, the star spangled banner, and, oh yes, George Washington, which was the image selected as most closely resembling the verbal description. We're not told what the other three choices were.

Further, the ganzfeld isn't "forced choice" as you seem to think it is, but "free-response". The difference being that in a free response test the subject doesn't know what any of the potential targets are untill after the sending phase is finished. If you would take the time to carefully read even just the first article I listed in my original post, you would know this.

Ah, I see, I misread that section, but...

You are still wrong that it is not forced choice.

From the second paper:

At the completion of the ganzfeld period, the receiver is presented with several stimuli (usually four) and, without knowing which stimulus was the target, is asked to rate the degree to which each matches the imagery and mentation experienced during the ganzfeld period. If the receiver assigns the highest rating to the target stimulus, it is scored as a "hit."

"Today informed skeptics no longer claim that the outcomes of psi experiments are due to mere chance because we know that some parapsychological effects are, to use skeptical psychologist Ray Hyman's words, "astronomically significant."(Radin, 97)

amherst

Wow. Impressive. A quote from a believer! Hardly what I asked for.

 

[amherst]

It has been noted that longer responses get a gretaer hit rate than those which a curt and short. I don't know why.

And sometimes, the subject would know the nature of the target, be it photo from National Geographic or a phsyical location.

Who carried out the 1997 meta-analysis you mentioned?

Are you claiming that a subject sometimes knew what the nature of the target would be before a session took place? If so, where did you get this information?

Radin carried out the meta-analysis.

amherst

 

[amherst]

I see you failed to read my amplifying links, so here is an excerpt:

I've read those articles before, and I read them again when you posted them. Nothing in them explains why a vague description of a target would spuriously inflate the hit rate. The suggestion is incredibly ridiculous. I suggest you read the ganzfeld reader comments section of the skepdic.

Ah, I see, I misread that section, but...

You are still wrong that it is not forced choice.

From the second paper:

You are making a fool of yourself. "At the completion of the ganzfeld period..." completion usually means after, doesn't it? AFTER the sending period, the reciever gets to see the set of targets, not before. That's what a free-response test is.

Wow. Impressive. A quote from a believer! Hardly what I asked for.

You seem to have failed to see the quote within the quote, "astronomicaly significant" was a remark made by Ray Hyman refering to the ganzfeld experiments. Do you not find odds against chance of over a million billion to one compelling enough to concede that chance isn't a factor?

amherst

 

[DaveW]

I've read those articles before, and I read them again when you posted them. Nothing in them explains why a vague description of a target would spuriously inflate the hit rate. The suggestion is incredibly ridiculous. I suggest you read the ganzfeld reader comments section of the skepdic.

Wow, you really must not have any imagination then. OK, if I get to ramble on about what the target might have been, I get a pretty good chance to get close after seeing what the choices were. I can't make it any more explicit.

You are making a fool of yourself. "At the completion of the ganzfeld period..." completion usually means after, doesn't it? AFTER the sending period, the reciever gets to see the set of targets, not before. That's what a free-response test is.

OK, now I am not even sure you have read your own evidence. Below I put in the whole paragraph that I took the previous quote from. To paraphrase, the receiver "meditates" while the sender "sends" for 30 minutes. Then the reciever is shown the targets. Then he rates which is closest (by the rambling method I presume).

The sender is sequestered in a separate acoustically isolated room, and a visual stimulus (art print, photograph, or brief videotaped sequence) is randomly selected from a large pool of such stimuli to serve as the target for the session. While the sender concentrates on the target, the receiver provides a continuous verbal report of his or her ongoing imagery and mentation, usually for about 30 minutes. At the completion of the ganzfeld period, the receiver is presented with several stimuli (usually four) and, without knowing which stimulus was the target, is asked to rate the degree to which each matches the imagery and mentation experienced during the ganzfeld period. If the receiver assigns the highest rating to the target stimulus, it is scored as a "hit." Thus, if the experiment uses judging sets containing four stimuli (the target and three decoys or control stimuli), the hit rate expected by chance is .25. The ratings can also be analyzed in other ways; for example, they can be converted to ranks or standardized scores within each set and analyzed parametrically across sessions. And, as with the dream studies, the similarity ratings can also be made by outside judges using transcripts of the receiver's mentation report.

You seem to have failed to see the quote within the quote, "astronomicaly significant" was a remark made by Ray Hyman refering to the ganzfeld experiments. Do you not find odds against chance of over a million billion to one compelling enough to concede that chance isn't a factor?

amherst

Paraphrasing someone makes him less of a believer?

 

[DaveW]

Do you not find odds against chance of over a million billion to one compelling enough to concede that chance isn't a factor?

amherst

To reiterate, I don't know the math that well, but seeing how hits were rated, I find the "hit rate" less than compelling.

 

[Ed]

Most informed skeptics do not believe chance to be a factor.

amherst

Quite right. Chance is rarely a factor in any paranormal finding.

 

[Interesting Ian]

I see you failed to read my amplifying links, so here is an excerpt:

quote:
--------------------------------------------------------------------------------
The Ganzfeld is set up so that an interpretation must be made of a verbal report from the test subject to be matched against an image allegedly sent telepathically to the subject. Thus, even if an image bears little or no resemblance to the verbal description, if it is selected as the one most closely resembling the image verbally described, then it counts as a hit. For example, here is a verbal description taken from Dr. Berger's website on the ganzfeld:

I see the Lincoln Memorial...
And Abraham Lincoln sitting there... It's
the 4th of July... All kinds of fireworks...
Now I'm at Valley Forge... There are
fireworks... And I think of bombs
bursting in the air... And Francis Scott
Key... And Charleston...

There are quite a few images that would "match" this description, since the description itself contains at least eight distinct images (the Lincoln memorial, Lincoln, 4th of July, fireworks, Valley Forge, bombs, Francis Scott Key, Charleston) to which one could easily add a couple more, such as the American flag, the star spangled banner, and, oh yes, George Washington, which was the image selected as most closely resembling the verbal description. We're not told what the other three choices were.

--------------------------------------------------------------------------------

Huh?? What the . . . . . ?? It's hard for me to comprehend how incredibly stupid this guy is who wrote this dictionary. And I'm by no means just going by this entry.

 

[DaveW]

You seem to have failed to see the quote within the quote, "astronomicaly significant" was a remark made by Ray Hyman refering to the ganzfeld experiments. Do you not find odds against chance of over a million billion to one compelling enough to concede that chance isn't a factor?

amherst

I think I found where Radin got his "astronimcally significant" quote, and the full context is, at best, hardly flattering: (from Skeptical Inquirer, March/April 1996)

In the four major meta-analyses of previous parapsychological research, the pooled data sets produced astronomically significant results while the correlation between successful outcome and rated quality of the experiments was essentially zero.

You can see the article here: http://www.csicop.org/si/9603/claims.html

So, it sounds to me like Ray Hyman says the results were spectacular, but the quality of the tests was horrible.

 

[DaveW]

Personally, my biggest gripe with the experiments as described is that it seems the targets are something with alot of information in them (movies, in some instances, or vivid, complex pictures), and that the receivers are allowed to ramble on during their answer. (It depends on which description of the test you look at; it seems that then, some judges rate the targets against the description, which seems like an even larger source of error by throwing another person's judgement in.) The combination of lots of information given by the receiver and the large amount of information given by the targets lends itself to lots of everlap and leeway on what could be scored a hit. Why not relatively simple targets and direct responses from the receivers (ie, target 1 through 4, no rambling descriptions)?

 

[T'ai Chi]

Quite right. Chance is rarely a factor in any paranormal finding.

Perhaps you could show us some examples of paranormal findings as you put it?

 

[Zep]

FWIW, meta-analysis of crap data and experimental results does not make them any less crap results.

You might care to have YET ANOTHER look at PEAR's own meta-analysis of 25 years of their own RV (remote viewing) experiments, in which they admitted, after doing the mathematics correctly at last, that there was nothing significant found to support the contention that it existed.

 

[amherst]

I think I found where Radin got his "astronimcally significant" quote, and the full context is, at best, hardly flattering: (from Skeptical Inquirer, March/April 1996)



You can see the article here: http://www.csicop.org/si/9603/claims.html

So, it sounds to me like Ray Hyman says the results were spectacular, but the quality of the tests was horrible.

In his essay, Rhetoric Over Substance: The Impoverished State of Skepticism, Charles Honorton wrote:

"The next line of criticism concerned the effects of procedural flaws on the study outcomes. In our meta-analysis of the ganzfeld studies, Hyman and I independendently coded each study's procedures with respect to potential flaws involving sensory cues, randomization method, security, and so on. Here Hyman and I did not agree: my analysis showed no significant relationship between these variables and study success, while Hyman claimed that some of the flaw variables, such as the type of randimization, did correlate with results. In his initial assessment, Hyman claimed there was a nearly perfect linear correlation between the number of flaws in the study and its success (Hyman, 1982); this analysis contained a large number of errors that Hyman later attributed to typing errors (communication to Honorton, November 29, 1982). Later, Hyman (1985) claimed a significant relationship between study flaws and outcomes based on a complex multivariate analysis. However, an independent psychological statistician described the analysis as "meaningless" (Saunders 1985). Finally, Hyman agreed that "the present data base does not support any firm conclusion about the relationship between study flaws and study outcome" (Hyman & Honorton, 1986, p. 353). Were our differences in flaw assessment simply reflections of our respective biases? Perhaps, but independent examination of the issue by non-parapsychologists has unanimously failed to support Hyman's conclusions (Atkinson, Atkinson, Smith & Bem. 1990; Harris & Rosenthal, 1988a, 1988b; Saunders, 1985; Utts, 1991). In an independent analysis using Hyman's own flaw codings, two behavioral science methodologists concluded, "Our analysis of the effects of flaws on study outcomes lends no support to the hypothesis that Ganzfeld research results are a significant function of the set of flaw variables" (Harris & Rosenthal, 1988b, p. 3)."


amherst

 

[Zep]

The PEAR study is dated Feb 2000, somewhat later than Honorton's essay.

(I note Honorton's work is not a scientific paper, just an essay.)

 

[amherst]

The PEAR study is dated Feb 2000, somewhat later than Honorton's essay.

(I note Honorton's work is not a scientific paper, just an essay.)

Zep, what do the PEAR remote viewing studies have to do with the ganzfeld experiments?

amherst