CHANCE News 2.21
        (12 December to 31 December 1993)


Prepared by J. Laurie Snell as part of the
CHANCE Course Project supported by the
National Science Foundation and the
New England Consortium for Undergraduate
Science Education.

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   "Statistics are the triumph of the
    quantitative method, and the quantitative
    method is the victory of sterility and death"

                               Hilaire Belloc



>>>>>==========>> John Finn suggested the first item: Taking your Chances: An Explanation of Risk Assessment and the Psychology of Worry Old Farmer's Almanac 1994, 220-222 Jon Vara This is a very nice, brief article about risk. Vara supplies details often left out when people give odds for rare events. For example, when giving the risk of being struck by a small meteorite, he mentions that in 1954 a Mrs. Hodges became the only human confirmed to have been struck by a falling extraterrestrial body. (A dog was killed by a three pound meteorite that fell on Egypt in 1911). In an average year, half a dozen small meteorites strike the Earth close enough to human observers to be recovered, but one's annual risk of being hit by one is estimated to be only one chance in 17 billion. Chances for a globally catastrophic asteroid strike are estimated to be much higher, one chance in 500,000 giving a respectable one chance in 7,000 over a 70 year lifetime. A number of interesting tables are given. For example, a table of risks estimated to increase the probability of a person'sdeath in any year by one chance in a million. From this you learn that traveling by bicycle ten miles, by car 300 miles or by jet 1,000 miles all increase your chance of death by one in a million. <<<========<<

>>>>>==========>> Frazier Will Remain No. 1 in Savvy. The New York Times, 15 December 1993, B14 Harvey Araton In discussing the fact that Frazier was about to lose his record of 14,617 points as a Knick to Ewing, Araton tells the following story: When Frazier was in college, a Southern Illinois Saluki, there was a practice-ending drill that required the five starters to hit 10 free throws consecutively, two apiece, before they could leave. Frazier, the star, was not the highest percentage shooter, nor was he able to focus like the others, who were capable of making 25, even 50, straight. Frazier said that despite this, he was always the last shooter up, gunning for 9 and 10, his teammates' fate in his hands. "By the time they got around to 6 and 7, then 7 and 8, the pressure was starting to mount," he said. "By the time they got to 9 and 10, everybody would be standing there, looking at me, saying, 'You better not miss.' " Matthew Poage pointed out that if they really wanted to get home sooner, they should have let the better free throw shooters go last. <<<========<<

>>>>>==========>> Study Links Miscarriages to Caffeine Consumption. The New York Times, 22 December 1993, A18 Tim Hilchey A study in the most recent Journal of the American Medical Association reports that drinking more than the amount of caffeine in three cups of coffee a day during pregnancy nearly triples the risk of a miscarriage. A study reported in the same journal in February suggested that drinking three or fewer cups of coffee a day did not increase the risk of miscarriage or affect fetal development. These studies were considered somewhat contradictory and an accompanying editorial attempts to explain how this might happen -- huge range in cup sizes, variability in caffeine content of coffee brewed in different places, etc. <<<========<<

>>>>>==========>> In Debate on Radiation Tests, Rush to Judgment is Resisted. The New York Times, 1 Jan 1994, 1-1 Gina Kolata Energy Secretary Hazel O'Leary has asked that an investigation be carried out on the studies done by government agencies and others in the 50's and 60's to determine the harmful effects of radiation. These include studies in which terminally ill patients were injected with lethal or near lethal doses of radiation to see its effects, prisoners were irradiated to learn what doses of X-rays made men sterile and mentally retarded children received trace amounts of radioactive minerals to study human metabolism. Experts point out that it is necessary to judge these experiments in the context of the time. Little was known about the danger of radiation; modern ethical standards and informed consent were not well established, and so on. They point out that the studies are not secret and in fact appear in current literature and help to determine, for example, the safe amount of radiation during chemotherapy. There is a curious debate going on about whether the data from these experiments should somehow be tagged and not used in a routine way. <<<========<<

>>>>>==========>> W. Edwards Deeming, Expert on Business Management, Dies at 93. The New York Times, 21 December 1993, B7 John Hellish The Quality Gospel According to Deming: A Man Revered for His Influence on Corporate Competitiveness in the U.S. and Japan. Financial Times, 30 December 1993, M8 Martin Dickson W. Edwards Deming died on December 20 at the age of 93. All major newspapers carried his obituary. These are two of the more complete discussions of his life. There was also an interesting interview with Myron Tribus about Deming on the radio show on National Public Radio? "All Things Considered" that can also be found in the full text articles. The New York Times article tells the familiar story of Deming's initial successes with quality control, first in Japan and then in the United States with Ford and Xerox. It mentions his general theory of management and his vigorous life, running workshops right up to the time of his death. The article in the Financial Times ties in Deming's work with others including his collaboration with the founder of quality control, Walter Shewhart, and Deming's co-worker in Japan, Joseph Duran, himself on his final tour at age 89. <<<========<<

>>>>>==========>> Is Industrial Statistics out of Control? Statistical Science, 8(4), November 1993, 356-409 David Banks. While the author does not limit himself to quality control, this article and the comments on it are good places to get a "non hype" view of the work of Deming and others in bringing quality control to industry. Some of Banks' statements are controversial, for example, his statement: >> That statistical methodology is >> responsible for the Japanese success >> story is a myth fostered by the 1980 >> NBC television special on the Deming >> story "If Japan Can, Why Can't We?" Banks feels that the ideas behind Total Quality Management (TQM) are useful, simple, and not deep. He remarks that "TQM has worked very successfully in diverse industries, and the nation's economic engine would doubtless run more smoothly if it were more widely employed." He goes on to say, however: "There are dangers in TQM. As implemented, it tends to be enshrined, and this stifles creative solutions." This assessment of TQM guarantees a lively response by the other well- known statisticians who act as discussants for Bank's article. A more positive view of TQM and of Deming's work is presented by Robert Hogg as one of the discussants. The article, and the discussion that follows it, provide a down to earth and insightful analysis of Total Quality Control , in particular, and industrial statistics in general. <<<========<<

>>>>>==========>> Breast Cancer Screening Under 50: Experts Disagree if Benefits Exist. The New York Times, 14 December 1993, C1 Gina Kolata Mammogram Debate Moving From Test's Merits to Its Cost. The New York Times, 27 December 1993, A1 Gina Kolata Eight studies in the past 30 years have consistently found that routine mammograms for women over 50 reduce the death rate from breast cancer by at least 25%, but have not found a significant reduction for testing in younger women. Combined, the studies include 173,000 women in their 40's. Considered as a group, the studies do not show a statistically significant advantage for those women who had mammograms. Based on these studies, the National Cancer Institute has changed its recommendation that women under 50 have mammogram tests. It now recommends that women under 50 be informed of the results of present scientific studies and be encouraged to make their own choice. Other agencies continue to recommend mammograms for women under 50 and this article provides expert opinions on both sides of this issue. Those who argue for testing remark that "it is better to be safe than sorry" and that women who do not have the test and later develop breast cancer will blame themselves. They also suggest that the studies are not all that convincing. They claim, for example, that the patients were not followed for a sufficiently long time and that mammogram techniques have significantly improved since these studies. On the other side, you have the arguments that the large number of false positives lead to unnecessary fears, additional testing and even surgery and that the expense for a small number of successes is huge. The second article emphasizes the economic issues. Using the number of women who had mammograms in 1990, it is estimated that the cost is about half a billion dollars. It is argued that, in thinking about a national health plan, this is a lot of money to spend on testing that has not been demonstrated to have statistically significant effect. Of course, some women under forty who develop breast cancer could have had it prevented by such tests. Thus, women argue that they should not be treated as a "statistic", but rather as a human being, and if they want to have a mammogram test, it should be paid for. This shapes up to be a mighty battle between those who feel that, if the line is not held here, it will never be held -- health care costs will continue to spiral -- and a powerful movement among women to do everything possible to decrease the very high mortality rate of breast cancer. <<<========<<

>>>>>==========>> Study Yields Best Evidence that Alcohol Helps the Heart. The New York Times, 16 December 1993, B15 Associated Press Men Should Quaff Five Bottles Of Wine a Week, Study Says. The Ottawa Citizen, 28 December 1993, A2 Peter Pallot The Times article discusses a study published in the current New England Journal of Medicine that showed that moderate alcohol consumption cuts heart attack risk in half. It is believed that this is because such moderate drinkers have about 15 percent higher levels of high-density lipoprotein (HDL) cholesterol than those who do not drink. HDL is said to prevent heart disease by cleansing the blood vessels of fatty buildups. The study questioned 340 recent heart attack victims about their drinking habits. They compared them with healthy people about the same age and sex. Consuming one to three drinks daily reduced the risk, but more than three drinks a day did not lower the risk further. The second article reports on a speech given by Sir Richard Doll. He spoke on his continued work with his 1954 study of doctors that first demonstrated that smoking caused lung cancer. Of the 40,000 male and female doctors in the smoking study, 12,000 men later recorded their drinking habits over a period of years. It was found that the healthiest were non- smokers consuming 20-29 units of alcohol weekly. Units are in terms of whiskey and I assume they mean a shot and 29 units corresponds to 4.8 bottles of wine or 14.5 pints of beer. Doll comments that U.S. studies have suggested a level of consumption that is only about half what he found to be optimal. All researchers point out the obvious dangers of drinking and do not suggest non-drinkers rush out and start drinking. <<<========<<

>>>>>==========>> The Power of Faith. Newsday, 21 December 1993, Discovery 61 Bob Keeler Dr. Larry Dossey was intrigued by a study in 1988 that was a double blind randomized experiment with 393 cardiac-care patients showing that cardiac patients prayed for by others did significantly better than the control group. It was published in the Southern Medical Journal (July 1988, 81(7)). Apparently, such studies are normally published in parapsychology journals. Dossey then took time out from his medical practice to review the literature on this subject and was convinced that the evidence for the effectiveness of prayer was overwhelming. (A colleague observed that he certainly prayed for the outcome of all of his experiments.) The results of Dossey's study can be found in his new book "Healing Words," published by Harper Collins. Theories like this have obtained a new respectability through the new HIH Office of Alternative Medicine that has begun funding in this area among others. We will probably be hearing more about this book from the Skeptical Inquirer. <<<========<<

>>>>>==========>> U.S. Survey Estimates Infections with HIV Outside Risk Groups. The New York times, 14 December 1993, C10 Lawrence K. Altman The usual estimate of one million people in the U.S. infected with the HIV virus comes from computer models and has come under attack as not being a reliable estimate. The first randomized survey to determine the number of HIV positive people in the U.S. was conducted with 7,782 individuals from 18 to 59 years old, randomly chosen from 44 communities throughout the country. Twenty-nine people (22 men and 7 women) were found to be infected giving an estimate of 0.39 percent. This would lead to an estimate of 550,000 in the country. This estimate is thought to be low because the response from young men was poor and because limits in the design of the survey excluded many people at high risk for infection -- the homeless, those living in hospitals, prisons and other institutions. Those who conducted the survey thought that the previous figure of one million was probably pretty good. <<<========<<

>>>>>==========>> For Stock Market Advice, Just Call the Meteorologist for Manhattan. Wall Street Journal, 12 December 1993, B1 Steve Stecklow Finance professor Edward M. Saunders at the University of Massachusetts analyzed 63 years of weather data in Manhattan and compared the data with the daily Dow Jones Industrial Average. The Dow was up 46% of the time on sunny days and 49.5% of the days when the weather was overcast or raining. Overall, it was down 48.5% of the days. Since 1982, the weather effect has been diminishing. Saunders attributes the change to the increasing globalization of market trading and the advent of futures trading in Chicago. On the days of both the 1929 and 1987 stock market crashes the weather on Wall Street was pleasant. Saunders' study appears in the December issue of the American Economic Review. <<<========<<

>>>>>==========>> Mudslinging on the Earth-Beat. The Amicus Journal, Winter 1994, 39-44 Francesca Lymna This is a report of a recent meeting of the Society of Environmental Journalists. There was a session on "backlash" and this article contains selections from speeches at this session. The point is made that environmental writers have often in the past become captives of environmentalists and written their articles in an advocacy manner without much critical analysis of the problem. Now, apparently, there is a danger the other way that these writers will become captives of the anti- environmentalists and become excessively skeptical of environmental hazards. The speakers all discuss the difficulties they have understating the concept of uncertainly and the extent to which they need to explain this concept to their readers in the context of the environmental issue they are reporting. <<<========<<

>>>>>==========>> Who's Really #1?: Choose Your Math and Get the Rankings You Want. Science News, December 18 & 25, 1993, 412-413 Ivars Peterson Anyone who has followed football at all this year is aware of the difficulty of deciding which college football team is the best in the country. This article describes some mathematical and statistical tools that have been used in trying to rank sports teams in general and football teams in particular. The most recent is a method developed by James Keener described in the March SIAM Review based on some earlier work of Joe Keller. Keller was trying to rank the SIAM journals using such information as the number of times they were cited by other publications. He wasn't very satisfied with the results, so applied his ranking techniques to baseball where he felt he had more success. Harvard statistician Hal Stern has studied the way that the New York Times and USA Today determine team rankings. Evidently, they keep their method a secret, but Stern feels that at least USA Today uses a fairly standard least squares method. He stresses that the method you should use depends upon whether you are using the rankings to predict outcomes of future games or to determine participation in a championship playoff. <<<========<<

>>>>>==========>> Here are several articles from our Boston reporter Bill Peterson.

Ask Marilyn. Parade Magazine, 26 December 1993, 9 Marilyn vos Savant >> Somehow you've overcome extreme odds >> and flipped 100 consecutive 'heads.' The >> chances of flipping another head on the next >> toss can't possibly be as great as 50-50, can >> they? writes a reader. Marilyn gives something of a Bayesian answer, saying that they're probably far greater than that, unless we're absolutely sure the coin is fair, in which case the chances would, indeed, be 50-50. <<<========<<

>>>>>==========>> A Short-Range Solution: Bahr Steps in for Sisson. The Boston Globe, 16 December 1993, 89 Ron Bourges Can we handle another sports story? This one describes the New England Patriots' addition of veteran place kicker, Matt Bahr, to give their inconsistent rookie Scott Sisson a break. The story reports that although Bahr's career field goal accuracy of 0.718 puts him ninth in league history, "this season Bahr is connecting at only a 0.615 rate (8 for 13), well below his career figure." It's easy to check that this year's "sample" is not large enough for the difference to be statistically significant under a simple binomial model. Bahr, at least, seems to be aware that these things aren't settled by hypothesis tests anyway, quoting another famous place kicker (Jan Stenerud) to the effect that you're always two misses away from retirement. <<<========<<

>>>>>==========>> Here is an extended quotation which seems appropriate for this month when Ed McMahon will be hawking the Publishers' Clearinghouse sweeps, and a number of even less reputable contests are in season! He was a few paces away from them when suddenly the group broke up and two of the men were in a violent altercation. For a moment they seems almost on the point of blows. "Can't your bleeding well listen to what I say? I tell you no number ending in seven ain't won for over fourteen months!" "Yes it 'as , then." "No, it 'as not! Back 'ome I got the 'ole lot of 'em for over two years wrote down on a piece of paper. I takes 'em down reg'lar as the clock. An' I tell you, no number ending in seven--" "Yes, a seven 'as won! I could pretty near tell you the bleeding number. Four oh seven, it ended in. It were February--second week in February." "February your grandmother! I got it all down in black and white. An' I tell you no number--" They were talking about the Lottery. Winston looked back when he had bone thirty meters. They were still arguing, with vivid, passionate faces. The Lottery, with its weekly pay-out of enormous prizes, was the one public event to which the proles paid serious attention. It was probable that there were some millions of proles for whom the Lottery was the principal if not the only reason for remaining alive. It was their delight, their folly, their anodyne, their intellectual stimulant. Where the Lottery was concerned, even people who could barely read and write seemed capable of intricate calculations and staggering feats of memory. There was a whole tribe of men who made a living simply by selling systems, forecasts, and lucky amulets. Winston had nothing to do with the running of the Lottery, which was managed by the Ministry of Plenty, but he was aware (indeed everyone in the Party was aware) that the prizes were largely imaginary." --George Orwell, "1984" <<<========<<

>>>>>==========>> 200% of nothing: an eye-opening tour through the twists and turns of math abuse and innumeracy. A.K. Dewdney Wiley, New York 1993. A. K. Dewdney, well known for his columns on Mathematical Games and on computing in the Scientific American, has written a book on numeracy. Through the years, his readers, who he calls "abuse detectives" have sent him interesting examples of the abuse of mathematics from the press. In this book, Dewdney presents many of these examples together with his ideas on what an average person should know about mathematics to avoid being misled by advertisements and news reports on television and in the newspapers. Not surprisingly, statistics and probability plays an important role in this. The title of the book came from an advertisement which claimed that a new light-bulb would save 200 percent on electricity costs. A reader wrote to the company suggesting that he should be paid for using the light- bulbs since, if the claim is correct, he would be generating electricity. <<<========<<

>>>>>==========>> !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! CHANCE News (12 December to 31 December 1993) !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Please send suggestions to: jlsnell@dartmouth.edu