Wednesday, March 23, 2005

THIS IS THE JOY OF SCIENCE

Reports of experiments like the one below, I love to copy out and read and to follow step by step as they are unfolded to me. Then to share them with others like yourselves. This is the joy of the scientific method, to see something revealed so clearly that, it's truth is clear to all. Nothing is more pleasurable to my sensibilities, I assure you. Sometimes, of course, more information reveals a even deeper truth here and there but nothing can match reading about and following in one's own mind the clear, incontrovertible moments of truth as the following two experiments demonstrate.

"The demand to “show me” can also be quite subtle. In the late] 1840s for example, Dr. Ignaz Phillipp Semmelweis noted that the rate of death from “childbed fever” among mothers who had given birth in a ward serviced by physicians was almost four times as high as mothers in a ward in the same hospital serviced by midwives. The deaths tended to occur in women in the same rows of beds. Semmelweis wondered whether the reason was that they were attended by the same doctor. The doctors didn’t clean their hands, even after returning from dissecting a cadaver in the morgue, because such practice was considered to be unmanly. Or perhaps the effect was psychological, since after a priest administered last rites to a dying patient, he went down the line of beds ringing the “death bell.” At Semmelweis’s request, the priest stopped ringing the death bell in the hospital, but the mothers continued to die in rows. Semmelweis then demanded that his colleagues and assistants wash their hands in solution of chlorine of lime before they examined a woman or delivered a baby. Over the next fifteen months, the death rate fell from 12 percent to 1.2 percent. After participating in a republican street demonstration in 1848, however, Semmelweis was fired from his hospital post. His successor stopped the silly requirement of hand washing, and the death rate rose to 15 percent. We would be more certain that the changes in death rate were due to hand washing if he had required the doctors to wash their hands in some randomly picked rows but not in others. Semmelweis happened nevertheless to be correct, and he tested it in a way that allowed him to present evidence to a person who demanded “show me.” Unfortunately, the medical people at the time were not as impressed as we believe in retrospect that they should have been. The old practices were retained until the 1880s, when Dr. Joseph Lister [ah, the wonders of Listerine] understood the importance of Semmelweis’s experiments. In the meantime, Semmelweis had lost his sanity, begun accosting people on the streets to warn them to stay away from doctors who didn't clean their hands, and died in a mental institution in 1865." (HOUSE OF CARDS, by Robyn Dawes, pp. 77-78)

[And right after his commitment the Civil War in America started. Could his commitment to an asylum have caused the Civil War? Within this set of brackets lies religious logic? Which will you trust?]

Another joy is to watch a scientific mind sort through the problems in developing ways to arrive at experiments and valid results. I once worked with a physicist in an experiment about gravity and to watch him work was a revelation and a joy. You can't escape a wonderful optimism in watching the process of arriving at truth with scientific methods just because scientific methods allow us to arrive at the only certainty in the world which has any verifiability by others. Everything else is mere subjective palaver, even my own palaver.

"How does a clinical judge integrate a positive test result in a medical test or an unusual response to a Rorschach Ink Blot Test with knowledge that a disease indicated by such results is extremely rare?

"Such integration cannot be done on an intuitive basis. Instead clinical judgment is often based on a number of cognitive “heuristics” rules of thumb. The first heuristic is to search one’s memory (including memory of one’s training) for instances similar to the one at hand. This heuristic is termed availability. Unfortunately, availability can be quite biased by selective exposure, selective recall, vividness of the instance or category recalled, and so on. A second heuristic is to match the cues or characteristics with a stereotype or a set of other characteristics associated with a category—a heuristic termed representativeness. The degree to which something matches a category, however, does not indicate how probable it is. For example, our stereotype of someone addicted to intravenous drugs is that such a person smokes marijuana; hence, marijuana-smoking is a characteristic that matches our stereotype of an intravenous drug addict—even though people who smoke marijuana are far more likely not to use intravenous drugs than to use them, let alone be addicted to them.

"Availability and representativeness are the heuristics that most commonly lead us to make poor judgments, but they are not the only ones." (H.O.C. p. 100)
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"Every government is run by liars and nothing they say should be believed." —I. F. Stone [Well—that's a bit harsh. If we all believed that sentiment all the time, we'd have anarchy. But in times like these when neocons have adopted and polished the practice of public lying to such a fine art, we should, at least, for the time being make Stone's warning our American watchword.]

1 comment:

Sausage said...

The lessons of statistical analysis and falisification had to wait until Fischer and Popper hammered them home. However, being an inductionist myself, I'd have to say that the dropping rate of infection was a huge clue to miss. A fun story!