Proving a Negative
Interesting comments:
http://www.the-scientist.com/yr2004/oct/research3_041025.html
The Scientist
Volume 18
Issue 20 | 26 | Oct. 25, 2004
Vision For Olfaction, a Hypothesis is Felled
With negative results comes silence where belief once stood
By Peter Mombaerts
Rarely do scientific studies claim that something is not the case.
Rarer still do negative results appear in top-tier journals. Yet two
recent papers in Nature describe what olfactory sensory neurons do not
do.
. . . .
PROVING A NEGATIVE Publication of these results is remarkable because they describe negative evidence. Scientific journals, particularly top-tier journals, want research articles to provide positive evidence for a hypothesis. Indeed, failure to obtain positive evidence for the tested hypothesis may be due to a failure of the test itself: trivial errors, technical inadequacies, or flawed design. But it is worthwhile to report negative evidence because it stimulates alternative thinking and can free scientists from misguided assumptions. During the course of this project, from 1999 to 2004, our experimental strategy was dominated by the concern that, after all, the sequence of OR loci is not modified in OSNs. Both Nature papers are a series of control experiments, and controls for control experiments, in an attempt to rule out that the favorite hypothesis, alas, is not correct.
But the experiments were carried out with only two of 1,200 OR genes. Perhaps we and our colleagues were unlucky, and selected OR genes that are not representative and do not undergo modifications. Perhaps nuclear transfer reverted the sequence modifications back to the germline configuration: The extensive nuclear reprogramming that occurs in the oocyte upon nuclear transfer may also erase the sequence alteration at the OR locus. Perhaps ... perhaps ...
NOW WHAT? Nonetheless, I believe that the hypothesis of DNA rearrangements in OR loci, which was already raised in the 1991 paper describing the discovery of OR genes,4 has been laid to rest with a sufficient degree of certainty. This was a pet hypothesis for many scientists working on this problem, including myself (many of us were immunologists once upon a time). OSNs and lymphocytes have solved the issue of gene choice in radically different ways. As to alternative hypotheses, I perceive a deafening silence. The enigma of OR gene choice appears to have receded even further.
(End quote)
***********************
Now if only the sCAM community would do this as a reaction to the myriad negative studies of their dubious methods. Since when have they ever abandoned a single nutty idea?
Normally ethical practitioners of medicine will drop a method that is proven to be unfounded. sCAM practitioners, OTOH, continue to use the dubious method. Even when some of the methods they use are actually reasonable, it amounts to them using 100% (of their quack methods, both unconfirmed and disproved), plus the reasonable methods. The dubious 100% doesn't get smaller. Instead their toolbox just gets filled with more methods - the 100% becomes 101%, then 102%, etc. Then they parade the infinitely little reasonable part of their practice to justfiy allowing them to remain in practice (while they will continue to practice their 100% junk, which never gets smaller).
"CAM practitioners often exploit the very mention of their name or modality in the media, research or regulations, even if the mention is in a negative context. If a research project has even just begun, they shout from the housetops that their modality has been scientifically proven to be efficacious. And when the completed research overwhelmingly disproves their modality, they ignore or criticize the research and continue to practice their quackery. If you loan them your shirt, they'll take your coat as well." - http://www.skepticreport.com/health/camdilemma.htm
On the condition that there is a qualified effort being made to find proof for a claim, the more time that goes by without finding any proof, the less compelling is the claim.
Chiropractic is just one example. The "chiropractic subluxation" (*) has no compelling proof for its existence. In fact, there are some very good reasons to suspect that there never will be found such evidence. The more time that goes by with trying to redefine chiropractic subluxations and prove their supposed existence, the heavier the accumulation of weight on the side of the scales, against it ever being proven.
The same applies - even more strongly - to homeopathy.
The NCCAM needs to quit it's wild goose chases and get its priorities straight. It should stop:
a. wasting our money on quackery and fictional diseases
b. taking it from legitimate research for real diseases
c. wasting the time of researchers,
d. confusing the public,
e. providing the ammunition being used by quacks to promote healthfraud and quackery
(*) Next post: "Chiropractic Oranges"
http://www.the-scientist.com/yr2004/oct/research3_041025.html
The Scientist
Volume 18
Issue 20 | 26 | Oct. 25, 2004
Vision For Olfaction, a Hypothesis is Felled
With negative results comes silence where belief once stood
By Peter Mombaerts
Rarely do scientific studies claim that something is not the case.
Rarer still do negative results appear in top-tier journals. Yet two
recent papers in Nature describe what olfactory sensory neurons do not
do.
. . . .
PROVING A NEGATIVE Publication of these results is remarkable because they describe negative evidence. Scientific journals, particularly top-tier journals, want research articles to provide positive evidence for a hypothesis. Indeed, failure to obtain positive evidence for the tested hypothesis may be due to a failure of the test itself: trivial errors, technical inadequacies, or flawed design. But it is worthwhile to report negative evidence because it stimulates alternative thinking and can free scientists from misguided assumptions. During the course of this project, from 1999 to 2004, our experimental strategy was dominated by the concern that, after all, the sequence of OR loci is not modified in OSNs. Both Nature papers are a series of control experiments, and controls for control experiments, in an attempt to rule out that the favorite hypothesis, alas, is not correct.
But the experiments were carried out with only two of 1,200 OR genes. Perhaps we and our colleagues were unlucky, and selected OR genes that are not representative and do not undergo modifications. Perhaps nuclear transfer reverted the sequence modifications back to the germline configuration: The extensive nuclear reprogramming that occurs in the oocyte upon nuclear transfer may also erase the sequence alteration at the OR locus. Perhaps ... perhaps ...
NOW WHAT? Nonetheless, I believe that the hypothesis of DNA rearrangements in OR loci, which was already raised in the 1991 paper describing the discovery of OR genes,4 has been laid to rest with a sufficient degree of certainty. This was a pet hypothesis for many scientists working on this problem, including myself (many of us were immunologists once upon a time). OSNs and lymphocytes have solved the issue of gene choice in radically different ways. As to alternative hypotheses, I perceive a deafening silence. The enigma of OR gene choice appears to have receded even further.
(End quote)
***********************
Now if only the sCAM community would do this as a reaction to the myriad negative studies of their dubious methods. Since when have they ever abandoned a single nutty idea?
Normally ethical practitioners of medicine will drop a method that is proven to be unfounded. sCAM practitioners, OTOH, continue to use the dubious method. Even when some of the methods they use are actually reasonable, it amounts to them using 100% (of their quack methods, both unconfirmed and disproved), plus the reasonable methods. The dubious 100% doesn't get smaller. Instead their toolbox just gets filled with more methods - the 100% becomes 101%, then 102%, etc. Then they parade the infinitely little reasonable part of their practice to justfiy allowing them to remain in practice (while they will continue to practice their 100% junk, which never gets smaller).
"CAM practitioners often exploit the very mention of their name or modality in the media, research or regulations, even if the mention is in a negative context. If a research project has even just begun, they shout from the housetops that their modality has been scientifically proven to be efficacious. And when the completed research overwhelmingly disproves their modality, they ignore or criticize the research and continue to practice their quackery. If you loan them your shirt, they'll take your coat as well." - http://www.skepticreport.com/health/camdilemma.htm
On the condition that there is a qualified effort being made to find proof for a claim, the more time that goes by without finding any proof, the less compelling is the claim.
Chiropractic is just one example. The "chiropractic subluxation" (*) has no compelling proof for its existence. In fact, there are some very good reasons to suspect that there never will be found such evidence. The more time that goes by with trying to redefine chiropractic subluxations and prove their supposed existence, the heavier the accumulation of weight on the side of the scales, against it ever being proven.
The same applies - even more strongly - to homeopathy.
The NCCAM needs to quit it's wild goose chases and get its priorities straight. It should stop:
a. wasting our money on quackery and fictional diseases
b. taking it from legitimate research for real diseases
c. wasting the time of researchers,
d. confusing the public,
e. providing the ammunition being used by quacks to promote healthfraud and quackery
(*) Next post: "Chiropractic Oranges"
posted by Sitemaster | 11:04 AM
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