"Extraordinary claims require extraodinary proof."
Given that ESP (by definition) contradicts a vast body of scientific
knowledge in both physics and biology, the onus is on the ESP investigators
to support their claims.
Given the small probability that all of modern physics is false, even small
likelihoods of error or fraud in ESP research must be given serious
consideration.
The whole point of experimentation is to eliminate the _possibility_ (yes,
I know that this is an unobtainable goal ;-) of alternative explanations.
It is not enough for an experimenter to say that "sensory leakage" was
possible, but not demonstrated. The onus is on the experimenter to show
that adequate procedures were used to rule out the poissibility of sensory
leakage (or whatever).
We must also consider false positives.
If you run enough experiments some will achieve statistical significance
even if nothing in fact happened beyond chance variation. Unless one can
quantify the number of unsuccessful attempts to demonstrate ESP (which are
not usually published), the published successful demonstrations must be
robust enough -- both in real physical effect size as well as in
statistical effect size -- to be convincing.
The smaller the effect size, the greater the likelihood that some flaw in
the experimental procedure allowed a spurious effect to occur.
For example:
If one is using a Rhine deck of cards to assess card guessing--
if one card is slightly flawed, it might provide enough of a (subliminable)
cue to produce a success rate of 5.1 rather than the chance rate of 5.0.
Over 10,000 trials this could be statistically significant (and ESP
experiments typically use large numbers of trials and show small effect
sizes).
An experimental flaw sufficient to cause a subject to consistently get 15
out of 25 correct would be much more detectable.
Hence, the skepticism by Blackmore and others is justified.
* PAUL K. BRANDON [EMAIL PROTECTED] *
* Psychology Dept Minnesota State University, Mankato *
* 23 Armstrong Hall, Mankato, MN 56001 ph 507-389-6217 *
* http://www.mankato.msus.edu/dept/psych/welcome.html *
