Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!watmath!clyde!caip!seismo!ut-sally!utastro!bill From: bill@utastro.UUCP (William H. Jefferys) Newsgroups: net.sci Subject: Parapsychology: S/N Ratios Message-ID: <969@utastro.UUCP> Date: Tue, 8-Jul-86 11:20:40 EDT Article-I.D.: utastro.969 Posted: Tue Jul 8 11:20:40 1986 Date-Received: Wed, 9-Jul-86 03:16:51 EDT Organization: U. Texas, Astronomy, Austin, TX Lines: 136 Topher Cooper remarks: > You seem to have a rather exaggerated concept of the size of > parapsychological experiments. It's true that the average > parapsychology experiment uses more data than the average > psychology experiment -- but not that much more. A very > big parapsychology experiment might involve 20000 trials. > More commonly an experiment has 1000 trials. I was responding to Dave Trissell, who was talking in the following terms: > Sorry, but I didn't state the case clear enough. Over equal > intervals of time the success rate usually varies from better > to worse. Thus, a 10,000 trial experiment when divided into > two 5,000 trail periods will find a higher sucess and > A machine I was tested on was built by a fellow Motorolan > and used a so-called noise diode which latched and recorded > up to 10,000 samples a second. 10,000 samples _a second_!!! How long does he run this thing anyway? > Some techniques which show great promise (though I think that > they are still in need of some maturing) seem to get statistically > significant results with only a few dozen trials. We'll have > to see how they work out. We shall see. If such techniques show paranormal effects in anyone's hands, it might be interesting. > There are two ways that "detectors become more sensitive". One > way is that they introduce less noise themselves. For example, > IR detectors may be cooled so that their is less internally > generated IR. This is certainly an important process but it > is not the dominant one. [Dissertation on how detectors move the signal-processing to a different place without changing the basic beginning-to-end processing] You are right, of course, but this is beside the point. Reducing the "noise" inherent in psi experiments is precisely what I am talking about. No one in their right mind would set up an experiment by deliberately injecting noise into their experiment that is a hundred times the size of the expected signal, just so that they can have the "fun" of pulling the signal back out of the noise. One doesn't take a CCD frame of a faint galaxy by flooding the chip with 100 x the flux that expected from the galaxy, just so that one has to stack 10,000 frames to pull the signal back out of the noise. Yet ever since Rhine, that is the basic paradigm that parapsychologists have been using. Not to denegrate Rhine. His idea of using statistical processing to study psi was for its time a revolutionary one. But here it is fifty years later, and parapsychologists using these techniques still can't convince other scientists that paranormal effects are real. Heck, they can't even convince some parapsychologists (e.g., Susan Blackmore). For example, why study PK by rolling dice (to give a simple example)? If a psychic can really exert enough force on the dice to affect the roll in a nonrandom way, surely he or she can exert enough psychic force on a sensitive torsion balance to move it measurably! If the psychic can't do the latter (under suitably controlled conditions), how can parapsychologists expect other scientists to accept the results of dice-rolling experiments as evidence for paranormal effects? If a psychic can't move a sensitive torsion balance, how can anyone take spoon-bending seriously? Or consider experiments based on Schmidt's ideas. Instead of trying to pull signal out of noise generated by quantum processes, why not see if the psychic can directly affect one of the very sensitive quantum detectors that have been developed? A SQUID comes to mind as a possible basis for such an experiment. If psychics can't affect a detector of that sensitivity in the same room with them, how can a general take seriously the proposal that psychics can somehow cause Soviet ballistic missles to fail at a distance of 5000 miles? After all, missile defence is useless if can only increase the probability of a missle failing by a small amount over the chance level. > The attitude of parapsychologists is that there is an unknown > source of systematic biases. No known source of such biases, > or combination of sources fit its characteristics very well. > Maybe someday we'll identify a subtle effect arising from > known processes, maybe not. But it is anti-scientific to > simply assume the effect arises from known causes or > to require full understanding *before* any effort be put > into investigating it. As long as one simply says "there are unexplained biases", that's fine. It is when the words, "...and those biases are evidence of paranormal phenomena" are added that I, and most scientists, part company with parapsychologists. > Bill Jefferys seems to agree that there are systematic biases. > He offers no explanation for them, but simply dismisses them > as, essentially, too small to worry about. > Too me, that isn't an attitude which is likely to advance > scientific understanding very much. I think this is a distortion of my position. In many cases in the past we know what the biases were (unconscious "cueing", or outright cheating, e.g., Soal). To their credit, many parapsychologists have made a real effort to tighten their controls. But how can we be sure that their efforts have been adequate? The question is not whether or not there are biases, but whether they are "interesting" or not. "Clever Hans" was very "interesting" science when the source of bias was first understood. Now it is old hat. And although you say ex-cathedra that no known biases or combination of biases fit the data very well, I think that that case has yet to be made. To get my interest, you will have to come up with something that (a) is replicable, (b) has a large enough signal that one can be certain that it is real, and not an artifact. If someone like Susan Blackmore says that an alleged paranormal phenomenon is worth looking at, then I would have to agree. (I have to use someone like her as a proxy, since I don't have time to waste in studying this subject closely. I have enough trouble keeping up in my own field.) -- Glend. I can call spirits from the vasty deep. Hot. Why, so can I, or so can any man; But will they come when you do call for them? -- Henry IV Pt. I, III, i, 53 Bill Jefferys 8-% Astronomy Dept, University of Texas, Austin TX 78712 (USnail) {allegra,ihnp4}!{ut-sally,noao}!utastro!bill (UUCP) bill@astro.UTEXAS.EDU. (Internet)