Exam 11: Inductive Reasoning

Analyze the following study according to the criteria set by your instructor: A study from the University of Health Sciences/Chicago Medical School suggests,says psychologist David E.Schotte,coauthor of the study,"that dieters have to learn to cope with stresses and emotional upsets in order to lose weight." Fifteen women who were frequent dieters and fifteen who dieted infrequently were all given a premeasured bag of popcorn,and then saw scenes from Halloween.After the screening,each bag was collected and reweighed.The habitual dieters ate more than twice as much popcorn as did the women who dieted infrequently. -Adapted from Sally Squires in the Washington Post

Evaluate the following generalization(s),identifying sample,population,attribute of interest,and the extent to which the claims involved are knowable.Consider carefully the size and diversification of the sample and the extent to which the population differs or may differ from the sample;remember,what's important is that the sample be representative. Stortz has heard from his friends that the folks in North Carolina are pretty friendly,so he looks forward to going through it on his bike trip to Florida.

Evaluate the following generalization(s),identifying sample,population,attribute of interest,and the extent to which the claims involved are knowable.Consider carefully the size and diversification of the sample and the extent to which the population differs or may differ from the sample;remember,what's important is that the sample be representative. A poll of fifty weight lifters at a southern California gym determined that thirty-three payed close attention to their diets as well as to their exercise.Of those thirty-three,twenty-five (50 percent of the original fifty)made it a point to eat more than the minimum daily amount of protein for large adults,and twenty (40 percent of the original fifty)took vitamin pills and other dietary supplements.The chain of health food stores that took the poll concluded that weight lifters constitute a substantial market for its products,since it is likely that 40 percent of all weight lifters across the country take vitamin pills and supplements and that an additional 10 percent are at least highly conscious of their diets.

Evaluate the following analogical argument: Mr.Naphal has read in an authoritative science report that a dye commonly injected into Florida oranges is carcinogenic.He resolves not only to avoid Florida oranges until he learns that they no longer are dyed with the same chemical,but also to avoid California oranges and all grapefruit as well.

With the same confidence level,a generalization from a larger sample will have

Analyze the following study according to the criteria set by your instructor: "Barbara Sherwin,director of a research team at McGill University,found that a small quantity of the male hormone testosterone,in addition to estrogen,led to a spicier sex life for some postmenopausal women.Twenty-two of the McGill team's subjects were given 150 milligrams a month of testosterone with estrogen,11 were given estrogen alone,and 11 took placebos.The testosterone group reported more desire and arousal and more frequent sexual thoughts than did the women in the other two groups.Though 17 percent of the testosterone recipients developed mild facial hair,this side effect receded when the dosage was reduced." -Elsie Rosner,Physician's Weekly,reported in Reader's Digest

Lin sends away for a hot-cold serving tray she has seen advertised.The tray is promised to keep hot dishes hot and cold dishes cold without electricity.Lin tries it out by placing a pan of hot beans on it.They stay hot throughout dinner."It works," she tells her husband. What causal claim (if any)is stated or implied in Lin's conclusion?

Consider the following passage: Julia sells exotic birds.She has placed four orders with wholesale bird supplier Papagayo Co. ,and all of them have been filled with healthy birds.Lately,however,some wholesale competitors have been trying to get her to order from them.But,when it's time to make the next order,she decides she's better off with Papagayo because she's pretty sure she'll get healthy birds.(Do not assume that you know anything about birds or the bird business. ) Given the original circumstances,which of these conclusions would produce the strongest argument?

Consider the following passage: Julia sells exotic birds.She has placed four orders with wholesale bird supplier Papagayo Co. ,and all of them have been filled with healthy birds.Lately,however,some wholesale competitors have been trying to get her to order from them.But,when it's time to make the next order,she decides she's better off with Papagayo because she's pretty sure she'll get healthy birds.(Do not assume that you know anything about birds or the bird business. ) If all the preceding orders had been for parrots,then her argument would be stronger if the new order was for

Evaluate the following argument in accordance with the criteria discussed in the text. I'd wash the car but for the fact that we don't need any more rain.

Evaluate the following generalization(s),identifying sample,population,attribute of interest,and the extent to which the claims involved are knowable.Consider carefully the size and diversification of the sample and the extent to which the population differs or may differ from the sample;remember,what's important is that the sample be representative. A random survey of 1,000 callers to a drug hotline number produced the following results:535 of the callers were heavy users of either cocaine freebase,amphetamines,or heroin;220 were "recreational" users of cocaine or hashish;92 were not drug users at all;and the remainder refused to answer the survey questions.This should put to rest the claim that most people who take drugs are of the occasional,"recreational" type.

Evaluate the following generalization(s),identifying sample,population,attribute of interest,and the extent to which the claims involved are knowable.Consider carefully the size and diversification of the sample and the extent to which the population differs or may differ from the sample;remember,what's important is that the sample be representative. Noting that recent scientific research suggests that a daily glass of wine or two might be good for the heart,Mr.Laub decides to tank up."Why in hell not," he says."If one glass of wine is good for you,most likely five or six is really good for you."

In a retrospective observational study,none of the members of the control group show the effect of the cause being investigated.

Evaluate the following argument in accordance with the criteria discussed in the text. "Four years ago,nonfat milk sold for 95 cents per half gallon.Today I paid $1.45 per half gallon from one of our low-priced supermarkets.That's a 52 percent increase in just four years for an average of 13 percent per year,while the official government inflation rate is less than 3 percent.Why is this? It's not coincidence that four years ago we got our first Republican governor in this state in a long time." -From a newspaper call-in column

A)Provide an informal analysis of the following passage;or B)in analyzing the passage,do the following: a.Identify the causal hypothesis at issue. b.Identify what kind of study it is. c.Describe the control and experimental groups. d.State the difference in effect (or cause)between control and experimental groups. e.Identify any problems in either the study or the report of it,including but not necessarily limited to uncontrolled variables. f.State the conclusion you think is warranted by the report. A study of 546 men in New Zealand who were identified as leukemia patients between 1979 and 1983 suggests that electrical workers are at increased risk of developing this cancer.Each man was matched with four other men from New Zealand's cancer registry.The study found a significant excess of leukemias among those electrical workers who had been employed as electronic equipment assemblers (4 cases,where only 0.5 would have been expected)and radio and television repairers (7 cases,where only 1.5 would have been expected).The study was conducted by N.E.Pearce and his colleagues at the Department of Community Health,Wellington Clinical School,and National Health Statistics Centre in Wellington,New Zealand. In a second study,Washington State epidemiologist Samuel Milham,Jr. ,obtained the death certificates for 95 percent of the 296 deceased Washington members of the American Radio Relay League (amateur radio operators)and 86 percent of the 1,642 deceased California members.Twenty-four of the deaths were due to leukemia;16 of these were of the myeloid class-nearly triple the 5.7 deaths that would have been expected from this type of leukemia.Milham acknowledges that the difference might be attributable to chance but points out that three other studies have revealed a tendency toward a relative increase in the acute myelogenous type of leukemia in electrical workers. -Adapted from Science News The first investigation,a retrospective observational study,suggests that something associated with working with electronics is a causal factor for leukemia in humans.The second,a prospective observational study,does not support the same thesis.But given the other studies mentioned,we would not think that further investigation of a possible link between leukemia and electrical work would be a waste of money.

Is the following a physical causal explanation or behavioral causal explanation? "They're not driving as much because they think the price of gas is too high."

Evaluate the following argument in accordance with the criteria discussed in the text. February 2 is Groundhog Day.If the groundhog sees his shadow,there'll be six more weeks of winter.If he doesn't,spring is right around the corner.

Analyze the following study according to the criteria set by your instructor: William Elliott,a University of Chicago physician,has found a link between diagonal creases in earlobes and risk of heart disease.He investigated twenty-seven groups of people,each group containing two pairs of individuals matched for age,sex,and race:one pair with established coronary heart disease and another pair of healthy people.A single member of each pair also had creased earlobes.After eight years,a significantly greater number of people with ear creases had died of heart disease,whether or not they were known to have heart disease at the start of the study. Elliott,who reported his findings at a meeting of the American Federation for Clinical Research,encourages other physicians to monitor patients with earlobe creases for symptoms of heart disease. -Adapted from Science News

Read and discuss the following report.In your discussion,identify the experimental and control groups,say whether there may be confounding variables in the study,and determine what the outcome probably was.(What does "no statistically significant difference" probably mean as it is used near the end of the report?) "A report released today said that a small,controlled study found magnets were no more effective than sham devices in treating chronic lower back pain. "But researchers note in the Journal of the American Medical Association that the negative result from an experiment with just 20 patients doesn't rule out the possibilities that magnets can help lower back pain or that magnet therapy can really work. "Such therapy has gained enormous popularity in recent years,despite little scientific evidence that the treatments work to relieve pain,improve circulation,or offer any other health benefits. "Celebrities,scores of books,and hundreds of Web sites promote the treatments,even though the Food and Drug Administration forbids any healing benefits to be claimed for them.By some estimates,more than $5 billion worth of therapeutic magnets have been sold worldwide. "A number of formal experiments,several supported by the National Institutes of Health,are under way to test magnets on a variety of painful chronic conditions. "The latest study,carried out by Dr.Edward Collacott of the Veterans Affairs Medical Center in Prescott,Arizona,and colleagues,is thought to be the first published experiment to use active and inactive magnets for more than a single episode of treatment,and for longer than 45 minutes. "All the patients in the study group had lower back pain,including the deformation of at least one articulating part of a vertebra.They had experienced pain in the same area of the back for an average of 19 years. "Each patient wore a flexible,rubberlike device for a total of six hours a day,three days a week,for two weeks.Each used an active bipolar magnet and an identical-looking,de-magnetized device for one week,but neither the patients nor the doctors treating them knew which therapy was being used. "The patients were questioned about their pain using a standardized questionnaire for pain measurement.Doctors also examined the patients more formally to determine the range of motion in the lower spine. "At the end of the study,the researchers found 'no statistically significant difference' between patients when they'd been wearing the real magnets or shams. "Collacott and his coauthors said more studies should be done to verify their results. "This was a pilot study and was not intended to prove or disprove the effectiveness of magnet therapy in general.Additional studies using different magnets,treatment times,and patient populations are needed." -Scripps Howard News Service

In controlled experiments,members of the experimental group are exposed to the suspected cause by