Exam 11: Inductive Reasoning

In prospective observational studies,we use "d" to stand for

Evaluate the following argument in accordance with the criteria discussed in the text. "After four years as an associate and brokerage manager with the New York life insurance consulting firm Kramer-Helgans,Sharon Brick noticed that she was being taken more seriously.It wasn't just because she'd done a great job,says Brick.She had changed her hair color from a dull brown to a lighter,more flattering sandy blond.Several months later,Brick was offered a partnership in the firm." -Working Woman

Juanita has taken six courses at Valley Community College,and she has a grade average of B so far.All the courses she has taken have been in sociology and psychology.She's thinking of enrolling in another course next term,and she expects to make at least a B in whatever she takes.Would Juanita's argument be stronger,weaker,or neither if we knew that the new course will be in psychology?

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. ) The original passage is

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. The cocktail Beatrice orders before dinner is watery,so she decides not to eat there after all."Don't think they can fix decent dinners if they can't even make a decent martini," she mutters.

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. "How come the people in these big motor homes always have a couple of midget dogs with them," Jasper wonders.

A sample is random if

Evaluate the following argument in accordance with the criteria discussed in the text. Studies indicate that close to 85 percent of university professors are liberal Democrats.It only stands to reason,therefore,that if you want to get a job as a college instructor,register as a Democrat.

A randomized controlled experimental study is

In generalizing from a sample,in order to achieve an error margin of plus or minus 3 percentage points at a confidence level of about 95 percent,what's the smallest random sample we can get away with,regardless of the size of the population?

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 we don't know what kind of bird she's about to order,we have the strongest argument if the previous orders were

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. Each year in the United States,a surgical procedure known as extracranial-intracranial arterial (EC/IC)bypass is done on three thousand to five thousand people who have had,or are at risk of,stroke.The operation,in which an artery on the scalp is attached to an artery on the brain to bypass a partial or total blockage,costs about $15,000.In a new study,researchers from the University Hospital in London,Ontario,examined 1,377 people who had recently had strokes or had signs of impending strokes.They randomly assigned 714 to get standard medical care and 663 to get EC/IC bypasses.The group that had the surgery subsequently had a slightly higher rate of stroke and death than the control group,according to the study. -Reported in the New England Journal of Medicine

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. As part of his work for NASA,Dr.Murdock was asked to find out what percentage of Americans saw Halley's comet when it was last visible.He randomly selected three cities-Seattle,Cleveland,and Boston-and polled several hundred randomly selected individuals from these cities.His findings are that fewer than 5 percent of Americans saw the comet.

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. Ronald is driving across the country when his car develops a minor mechanical problem.He can fix the trouble himself,but he'll need a wrench of a size he doesn't have.He resolves to stop at the next Sears retail store he sees to purchase one.He's been in four or five Sears retail stores in the past,and all of them have carried automotive tools.So he is confident that all Sears retail outlets stock them.

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. In a study of telephone operators in North Carolina,Suzanne Haynes of the National Center for Health Statistics in Hyattsville,Maryland,compared 278 women who worked all day at video display terminals (VDTs)with 218 clerical workers in the same companies who did not use VDTs.Twice as many VDT users reported chest pains as clerical workers in the same companies-20 percent compared to 10 percent.Perhaps,Haynes commented,"VDTs can be the ultimate nonsupportive boss." -Adapted from Science News

Evaluate the following argument in accordance with the criteria discussed in the text. Are body lice a cause of good health? So it seemed to the people in New Hebrides Islands,according to John Allen Paulos's comment in his book Innumeracy.After all,when body lice departed,people became ill.

Evaluate the following argument in accordance with the criteria discussed in the text. "Of course he was outdoors Wednesday,Watson.That's the only day there has been rain,and he had a good bit of dried mud on the heels of his boots."

Evaluate the following analogical argument: he:Let's leave Cincinnati for the golden West! Why don't we move to Los Angeles? she:Well,for one thing,we couldn't afford to buy a house there. he:Don't be such a pessimist.We bought this house here,didn't we? How much more expensive can houses in Los Angeles be?

In the following passage,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.Would our professor's conclusion,"About 32 percent of college faculty nationwide maintain home offices," be more likely if she had included faculty from other institutions among her survey? Why? A college professor converted one room of her house into a home office and intended to deduct her expenses on her federal income tax return.She wondered how many other college faculty had done the same,thinking that the more who deducted home offices,the less likely her own return would be noticed by the IRS and hence the less likely she would be audited.So she decided to do her own informal survey of her colleagues to see how many of them had home offices.She sent out a questionnaire of three questions to all 1,200 instructors at her campus,and she received 950 responses.(Her promise to share the results of the survey apparently motivated faculty to respond. ) As it turned out,32 percent of her respondents answered yes to the question,"Do you maintain an office at home?" Half of these also answered yes to the question,"Do you deduct your home office expenses on your federal income tax return?" And 24 percent of the entire group of respondents answered yes to the question,"Is your campus office adequate?"

Johnson is hired by a company to see if a new product,Topocal,will cause hair to grow on the heads of bald men.He recruits one thousand bald men,and randomly divides them into two groups:Five hundred (group A)rub Topocal on their scalps each day;the other five hundred (group B)rub a standard skin lotion on their scalps each day.After two months,Johnson checks to see what the results have been.He finds that there has been hair growth in 7 percent of group A and in 2 percent of group B.The category that best fits this study is