[extropy-chat] ESP controls

[Damien Broderick]

At 02:07 PM 2/11/2007 -0500, Ben wrote:

>my  main worry with psi experiments is whether there's a
>powerful "dataset selection" effect.
>
>I.e., if someone does a psi experiment and doesn't get positive results,
>they won't tell anyone and won't publish the results

This is the very well-known and well-characterized "file drawer" effect.

>I assume that statisticians studying psi experiments have attempted to
>account for this phenomenon, but I don't know exactly how they have done
>so....

Yes, of course they have. The topic remains somewhat controversial 
among statisticians, but Prof. Jessica Utts mentions it at, for 
random example, http://anson.ucdavis.edu/~utts/91rmp.html  < 
Following Rosenthal (1984), the authors calculated the "fail-safe N" 
indicating the number of unreported studies that would have to be 
sitting in file drawers in order to negate the significant effect. 
They found N = 14, 268, or a ratio of 46 unreported studies for each 
one reported. >  Given how time-intensive these trials are, and how 
few labs are doing them, such a "cover up" is extremely unlikely.

>The level of BS in the psi literature is far higher than in the CF
>literature

I seriously doubt that. One has to use some elementary common sense 
in segregating serious work (done at Princeton and Edinburgh 
universities, for example) from the idiots, telephone "psychics" and 
psychotic bloggers and from exploratory work later improved after 
review and criticism. Once the obvious anecdotal and new age woowoo 
has been filtered out or simply ignored as irrelevant, the bulk of 
the work I've read has been increasingly solid over the last 20 or 30 
years. I anticipate publications in the heavy duty science journals 
on the topic of "precognitive presentiment" within the next year or 
two--the data looks good, and replicability is getting better all the 
time (within the bounds of a stochastic effect). One of the features 
I like about presentiment is that significant responses *in advance 
of stimuli* can and has been found in old instrumented response data 
prepared by neuroscientists such as Damasio for entirely different 
purposes (as one would expect if the phenomenon is real).

Damien Broderick