Exam 11: Performance Evaluation Revisited: a Balanced Approach

Evaluate the following argument in accordance with the criteria discussed in the text. The packages that we gave our friend Debbie are undamaged, while the packages we sent through Ted suffered damage. We learned a lesson: Don't let Ted handle any packages. He is extremely careless.

An experiment in which subjects are randomly assigned either to an "experimental group" or a "control group" is called a

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 argument in accordance with the criteria discussed in the text. A lottery winner, asked why he thought he had won a major prize, pulled a small rhinestone four-leaf clover out of his pocket and said, "I think this had a lot to do with it."

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 1960, Dutch researchers from the University of Leiden questioned 852 men and their wives about the men's diets and then monitored the men for the next twenty years. They found that the death rate from heart disease was more than 50 percent lower among men who ate at least thirty grams (one ounce) of fish per day compared with men who ate no fish. Just one or two fish dishes a week, the researchers say, "may be of value in the prevention of coronary heart disease." -Adapted from Science News

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."

Make this inductive (statistical) syllogism into a strong argument by supplying an appropriate premise or conclusion: Most people with old cars have financial problems, so Anne and Dennis must be struggling financially.

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 attribute of interest here is

Evaluate the following argument in accordance with the criteria discussed in the text. See? When she has a good day at the store and sells lots of clothes, she always is in a good mood. It just shows you how effective a good mood can be in the sales business. The customer eats that stuff up.

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 survey was made in 1948 in which a large number of names were randomly selected from the telephone book of a large city. The individuals called were asked whether they preferred Truman or Dewey in the presidential race. Over half of the respondents named Dewey, so the pollsters concluded that Dewey would carry the city and region.

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.

Is the following a physical causal explanation or behavioral causal explanation? "She believes that she contributes to global warming each time she drives, so she walks to work."

"An FBI study of thirty-five serial killers [killers of several people, not all at once] revealed that twenty-nine were attracted to pornography and incorporated it into their sexual activity, which included serial rape and murder." This assertion, taken from an antipornography ad, seems to have been intended to show that pornography is a causal factor of serial rape and murder. Does it show that?

The claim "Fouled spark plugs kept the car from starting" implies that the car would have started if the spark plugs had not been fouled.

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. Is Lin using good causal reasoning?

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 at 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 a coincidence that four years ago we got our first Republican governor in this state in a long time." -From a newspaper call-in column

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 men (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.What is the sample?

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. BOSTON-AP, UPI reports (adapted). The constant bright lights of hospital nurseries, often two to four times as bright as normal office lighting, may contribute to the blinding of hundreds of premature babies each year, a recent study warns. Doctors kept track of the incidence of retinopathy, a disease of the retina, in two groups of premature babies. One group was kept in incubators covered with acetate that reduced the amount of light by 58 percent. The rest stayed in ordinary incubators. Among the smallest babies, the researchers found that twenty-one of thirty-nine (54 percent) in shielded incubators developed retinopathy, compared with eighteen of twenty-one (86 percent) of those exposed to the bright lights. Dr. Penny Glass, a developmental psychologist at Children's Hospital National Medical Center and Georgetown University Medical Center, who directed the study, recommends that the light levels in hospital nurseries be brought down. "I feel that the increase in light levels has not been demonstrated safe," she said.

Analyze the following study according to the criteria set by your instructor: A study published in the New England Journal of Medicine concludes that the number of handgun deaths in Vancouver, British Columbia, between 1980 and 1986 was less than one-fifth that of Seattle, 120 miles to the south. Seattle's population is approximately 490,000, whereas Vancouver's is about 43

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. "Exercise can temporarily disrupt a woman's menstrual cycle, according to Boston University research published in the May 23 [1985] New England Journal of Medicine. The researchers monitored the daily hormone levels in 28 college women who did not exercise regularly and had a history of regular menstrual cycles. The women were then sent to summer camp and participated in a rigorous exercise program-an initial 4-mile daily run, working up to 10 miles a day after five weeks, in addition to three and one-half hours daily of moderate sports such as biking or tennis. Only four, three of whom were on a high-calorie weight maintenance diet, had a normal menstrual cycle during that time. The researchers concluded that, regardless of whether the women lost weight, strenuous exercise disrupted their reproductive function. 'If very active women are having trouble getting pregnant, they probably should slow down intense exercise,' says exercise physiologist Gary Skrinar of BU." -Science News