[ExI] Psi (no need to read this post you already knowwhatitsays)
thespike at satx.rr.com
Fri Jan 8 06:33:57 UTC 2010
On 1/8/2010 12:07 AM, Max More wrote:
> How many negative trials were *not* reported.
By "negative trials" I assume you mean something like "runs of trials
with outcomes that were not significantly different from mean chance
expectation." By "not reported" I assume you mean "deceptively hidden or
discarded." My estimate in this case: None of them. Nobody has ever
questioned Dr. Sheldrake's probity (although some of his theories are
pretty hard to take seriously). Well, Randi did, once, until he was
shown to have lied.
> In Psi experiments, we
> rarely hear about "the silent evidence"
In analyses of psi experiments by anomalies researchers, actually we
hear all the time about the likelihood and magnitude of what is termed
"the file drawer." That's where non-significant results are supposed by
critics to be hidden away. The reality is that the file drawer can't
*possibly* hide sufficient dud data to account for the observations. I
take it you have reason to doubt this; what is your evidence?
Here's Dean Radin's THE CONSCIOUS UNIVERSE (not a bad summary) on the
file-drawer effect (selective reporting) in one major protocol, and this
is now standard: (page 79-80)
“Another factor that might account for the overall success of the
ganzfeld studies was the editorial policy of professional journals,
which tends to favor the publication of successful rather than
unsuccessful studies. This is the “file-drawer” effect mentioned
earlier. Parapsychologists were among the first to become sensitive to
this problem, which affects all experimental domains. In 1975 the
Parapsychological Association’s officers adopted a policy opposing the
selective reporting of positive outcomes. As a result, both positive
and negative findings have been reported at the Paraspsychological
Association’s annual meetings and in its affiliated publications for
over two decades.
Furthermore, a 1980 survey of parapsychologists by the skeptical British
psychologist Susan Blackmore had confirmed that the file-drawer problem
was not a serious issue for the ganzfeld meta-analysis. Blackmore
uncovered nineteen complete but unpublished ganzfeld studies. Of those
nineteen, seven were independently successful with odds against chance
of twenty to one or greater. Thus while some ganzfeld studies had not
been published, Hyman and Honorton agreed that selective reporting was
not an important issue in this database.
Still, because it is impossible to know how many other studies might
have been in file drawers, it is common in meta-analyses to calculate
how many unreported studies would be required to nullify the observed
effects among the known studies. For the twenty-eight direct-hit
ganzfeld studies, this figure was 423 file-drawer experiments, a ratio
of unreported-to-reported studies of approximately fifteen to one.
Given the time and resources it takes to conduct a single ganzfeld
session, let alone 423 hypotheitcal unrepoted experiments, it is not
surprising that Hyman agreed with Honorton that the file-drawer issue
could not plausibly account for the overall results of the psi ganzfeld
database. There were simply not enough experimenters around to have
conducted those 423 studies.
Thus far, the proponent and the skeptic had agreed that the results
could not be attributed to chance or to selective reporting practices.”>
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