Deck 6: Gathering Useful Data for Examining Relationships

Question 1

Use the following information for questions:
Decide if the study is an observational study or an experiment.

-Twenty blue-fin tuna were randomly assigned to two tanks of water, 10 tuna in each tank. One tank was polluted with methyl mercury, while the other tank was not polluted. The survival times of the fish in the two tanks were compared.

A) Observational Study
B) Experiment

Answer 1

Experiment

Question 2

Use the following information for questions:
Decide if the study is an observational study or an experiment.

-A biologist measured the increasing amounts of phosphorus in Lake Erie and observed a decreasing number of lake trout over a 5-year period.

A) Observational Study
B) Experiment

Answer 2

Observational Study

Question 3

Use the following information for questions:
Decide if the study is an observational study or an experiment.

-A study compared the IQ from children whose mothers smoked to the IQ from children whose mothers didn't smoke.

A) Observational Study
B) Experiment

Answer 3

Observational Study

Question 4

Use the following information for questions:
Decide if the study is an observational study or an experiment.

-Thirty-six students were randomly assigned to listen to Mozart (18 students) or a relaxation tape (18 students). The IQ of the students were measured afterwards.

A) Observational Study
B) Experiment

Question 5

Use the following information for questions:
Decide if the study is an observational study or an experiment.

-A medicine to remove the redness in eyes was tested in a group of 100 students. Each student took the medicine in one eye and a placebo in the other eye. The eye (left or right) that received the placebo was decided by flipping a coin.

A) Observational Study
B) Experiment

Question 6

Use the following information for questions:
Decide if the study is an observational study or an experiment.

-A study compared a group of men who had heart attacks with a similar group of controls. The proportion of men with male pattern baldness was compared between the two groups.

A) Observational Study
B) Experiment

Question 7

Use the following information for questions:
Decide if the study is an observational study or an experiment.

-100 students were followed over a 6-month period. The number of students who took Echinacea (a herbal supplement) and the number who developed colds were recorded.

A) Observational Study
B) Experiment

Question 8

Use the following information for questions:
Decide if the study is an observational study or an experiment.

-A sample survey of 100 voters was used to compare the proportion of women in the Democratic and Republican parties.

A) Observational Study
B) Experiment

Question 9

Use the following information for questions:
Decide if the study is an observational study or an experiment.

-To investigate how trans fat consumption might affect fertility, researchers analyzed data available from 18,555 healthy women who participated in the Nurses' Health Study between 1991 and 1999.

A) Observational Study
B) Experiment

Question 10

Use the following information for questions:
Decide if the study is an observational study or an experiment.

-One hundred adults who had either Type 1 or Type 2 diabetes were randomly divided into 2 groups to determine if the inhalable version of insulin is able to manage blood sugar levels just as well as injected insulin.

A) Observational Study
B) Experiment

Question 11

Use the following information for questions:
A researcher asked random samples of 50 kindergarten teachers and 50 12th grade teachers how much of their own money they spent on school supplies in the previous school year. They wanted to see if teachers at one grade level spend more than teachers at the other grade level.

-In this study, the grade level taught (kindergarten or 12th grade) is an example of

A) a randomly assigned treatment.
B) an explanatory variable.
C) a response variable.
D) a normal variable.

Question 12

Use the following information for questions:
A researcher asked random samples of 50 kindergarten teachers and 50 12th grade teachers how much of their own money they spent on school supplies in the previous school year. They wanted to see if teachers at one grade level spend more than teachers at the other grade level.

-In this study, the reply to the question about amount spent on school supplies is an example of

A) a randomly assigned treatment.
B) an explanatory variable.
C) a response variable.
D) a normal variable.

Question 13

Use the following information for questions:
A researcher asked random samples of 50 kindergarten teachers and 50 12th grade teachers how much of their own money they spent on school supplies in the previous school year. They wanted to see if teachers at one grade level spend more than teachers at the other grade level.

-In this study, it turns out that 12^th grade teachers generally earn more money than kindergarten teachers. The variable 'income of the teacher' is an example of

A) a dependent variable.
B) a confounding variable.
C) a response variable.
D) a normal variable.

Question 14

A researcher conducts a study to determine whether or not taking Vitamin C prevents colds. What is the explanatory variable in this study?

A) Whether or not one takes Vitamin C.
B) Whether or not one gets colds.
C) Whether or not one is a participant in the study.
D) Whether or not one knows which treatment one is taking.

Question 15

In an observational study, confounding means

A) having more than one response variable.
B) that the effect of the explanatory variable on the response variable changes for different categories of a third variable.
C) that the effects of several variables are tested at one time.
D) that the effect of the explanatory variable on the response variable can't be separated from the effect of other variables on the response.

Question 16

Which of the following is true about confounding variables in observational studies?

A) If a confounding variable is present, then we know that a change in the explanatory variable cannot cause a change in the response variable.
B) If a confounding variable is present, it is possible that a change in the explanatory variable causes a change in the response variable, but it is hard to separate the effect of the explanatory variable and the effect of the confounding variable on the response.
C) Confounding variables are not a problem in observational studies because we only observe the explanatory and response variables.
D) Confounding variables are only a problem in observational studies if they are also interacting variables.

Question 17

A study was conducted to compare the grade point averages (GPAs) of male and female students majoring in Psychology. In this study

A) gender and GPA are both response variables.
B) gender and GPA are both explanatory variables.
C) GPA is an explanatory variable and Gender is a response variable.
D) gender is an explanatory variable and GPA is a response variable.

Question 18

A medical doctor is comparing two treatments for high cholesterol. She puts the names of 40 patients with high cholesterol into a box, and randomly draws the names of 20 patients. These 20 patients are given treatment 1. The doctor gives treatment 2 to the remaining 20 patients. What type of study design is this?

A) Observational study
B) Sample survey
C) Randomized experiment
D) Significant

Question 19

Use the following information for questions:
Research is done to see whether taking oral contraceptives increases women's blood pressures. The blood pressures of women who take oral contraceptives are compared to the blood pressures of women who do not take oral contraceptive. A complicating factor is that the women who take oral contraceptives tend to be younger than the others. This must be taken into account because blood pressure increases with age.

-Which variable is the response variable in this study?

A) Age
B) Blood pressure
C) Oral contraceptive use
D) Both age and oral contraceptive use are response variables in this study.

Question 20

Use the following information for questions:
Research is done to see whether taking oral contraceptives increases women's blood pressures. The blood pressures of women who take oral contraceptives are compared to the blood pressures of women who do not take oral contraceptive. A complicating factor is that the women who take oral contraceptives tend to be younger than the others. This must be taken into account because blood pressure increases with age.

-Which variable is a confounding variable in this study?

A) Age
B) Blood pressure
C) Oral contraceptive use
D) There are no confounding variables in this study.

Question 21

An experiment is usually preferred to an observational study because

A) one can draw a cause and effect conclusion in an experiment but not in an observational study.
B) it is easier to collect data from an experiment than it is from an observational study.
C) it is cheaper to run an experiment than it is to do an observational study.
D) volunteers can be used for an experiment but not for an observational study.

Question 22

An observational study is done to see if eating at least two apples a week helps prevent tooth decay in children. However, the researchers are aware that children who eat apples may also drink less soda, so they measure soda consumption as well. In this example, soda consumption is an example of

A) an interacting variable.
B) an explanatory variable.
C) a response variable.
D) a confounding variable.

Question 23

Use the following information for questions:
For each relationship (conclusions from one or more studies), define what the response and explanatory variables are.
-The average life expectancy in Russia dropped from 64 years (1991) to 57 years (1995). One theory was that radiation from nuclear fallout was responsible.

Question 24

Use the following information for questions:
For each relationship (conclusions from one or more studies), define what the response and explanatory variables are.
-Children who take the time to eat breakfast get higher grades in school than children who don't eat breakfast.

Question 25

Use the following information for questions:
For each relationship (conclusions from one or more studies), define what the response and explanatory variables are.
-The oldest child in a family is more likely to favor the death penalty than the middle or youngest child.

Question 26

Use the following information for questions:
For each relationship (conclusions from one or more studies), define what the response and explanatory variables are.
-Second hand smoke (passive smoke) is a risk factor for chronic lung disease.

Question 27

Use the following information for questions:
For each relationship (conclusions from one or more studies), define what the response and explanatory variables are.
-Listening to Mozart raised non-verbal IQ scores an average of 8 to 9 points higher than listening to relaxation tapes.

Question 28

Use the following information for questions:
For each relationship (conclusions from one or more studies), define what the response and explanatory variables are.
-College instructors with a Ph.D. degree earn, on average, more than college instructors with only a Master's degree.

Question 29

Use the following information for questions:
For each relationship (conclusions from one or more studies), define what the response and explanatory variables are.
-Course grades based on student evaluations varied across the various fields. Social science courses generally received higher scores than natural science courses.

Question 30

Use the following information for questions:
For each relationship (conclusions from one or more studies), define what the response and explanatory variables are.
-Drinking as little as two cups of coffee before exercising limits the blood flow to the heart. An experiment with 18 young adults showed that when the subject remained inactive, the caffeine had very little affect, but after the subject participated in exercise, the caffeine slowed down the blood flow to the heart.

Question 31

Which of the following methods is not a good randomization procedure?

A) Using a computer to generate a list of random numbers.
B) Using a table of random numbers.
C) Flipping a coin.
D) Asking someone to pick numbers randomly between 1 and 10.

Question 32

The purpose of having a control group in a study is

A) to estimate the response when the treatment is not applied.
B) to decrease the margin of error.
C) to be able to blind the subjects.
D) to make the samples more representative.

Question 33

Eighty individuals who wished to lose weight were randomly divided into two groups of 40. One group was given an exercise program to follow while the other group was given a special diet. After three months, the researcher compared mean weight losses in the two groups. What type of study is this?

A) Observational study
B) Repeated measures study
C) Matched pairs study
D) Randomized experiment

Question 34

Use the following information for questions:
Sickle-cell disease is a painful disorder of the red blood cells that in the United States affects mostly blacks. To investigate whether drug A can reduce the pain associated with sickle-cell disease, a study by the National Institutes of Health randomly assigned 150 sickle-cell sufferers to receive the drug. Placebos were given to another 150 sickle-cell sufferers. Great care was used to ensure that the 300 participants did not know if their pill contained the drug. At the end of the treatment period, the researchers counted the number of episodes of pain reported by each subject.

-What type of study is this?

A) Observational study
B) Randomized experiment
C) Matched pairs study
D) Repeated measures study

Question 35

Use the following information for questions:
Sickle-cell disease is a painful disorder of the red blood cells that in the United States affects mostly blacks. To investigate whether drug A can reduce the pain associated with sickle-cell disease, a study by the National Institutes of Health randomly assigned 150 sickle-cell sufferers to receive the drug. Placebos were given to another 150 sickle-cell sufferers. Great care was used to ensure that the 300 participants did not know if their pill contained the drug. At the end of the treatment period, the researchers counted the number of episodes of pain reported by each subject.

-What is the response variable in this study?

A) Sickle-cell disease status (yes or no).
B) Form of drug (pill or liquid).
C) The number of episodes of pain.
D) The number of red blood cells.

Question 36

Use the following information for questions:
Sickle-cell disease is a painful disorder of the red blood cells that in the United States affects mostly blacks. To investigate whether drug A can reduce the pain associated with sickle-cell disease, a study by the National Institutes of Health randomly assigned 150 sickle-cell sufferers to receive the drug. Placebos were given to another 150 sickle-cell sufferers. Great care was used to ensure that the 300 participants did not know if their pill contained the drug. At the end of the treatment period, the researchers counted the number of episodes of pain reported by each subject.

-Which of the following principles was not used in this study?

A) Control
B) Blinding
C) Randomization
D) Blocking

Question 37

Use the following information for questions:
A researcher is studying the relationship between sugar consumption and weight gain. Twelve volunteers were randomly assigned to one of two groups. The first group had five participants which were put on a diet low in sugar and the other group with the remaining seven participants received 10% of their calories from sugar. After 8 weeks, weight gain was recorded from each participant.

-Which variable is the response variable in this study?

A) Sugar consumption
B) Diet low in sugar
C) Weight
D) Weight gain

Question 38

Use the following information for questions:
A researcher is studying the relationship between sugar consumption and weight gain. Twelve volunteers were randomly assigned to one of two groups. The first group had five participants which were put on a diet low in sugar and the other group with the remaining seven participants received 10% of their calories from sugar. After 8 weeks, weight gain was recorded from each participant.

-Which of the following principles was not used in this study?

A) Repeated measures
B) Blinding
C) Randomization
D) Control

Question 39

Use the following information for questions:
A researcher is studying the relationship between sugar consumption and weight gain. Twelve volunteers were randomly assigned to one of two groups. The first group had five participants which were put on a diet low in sugar and the other group with the remaining seven participants received 10% of their calories from sugar. After 8 weeks, weight gain was recorded from each participant.

-The 'low sugar' group can be thought of as a control group. The control group is being used in this experiment to avoid

A) Confounding with the '10% sugar' group
B) Placebo effect
C) Nonresponse bias
D) Replication

Question 40

Use the following information for questions:
Fifty university students are randomly chosen from the college campus. Their physical fitness routines and academic performance will be assessed. They are asked to maintain a diary over a semester to record their physical activity (i.e. work-outs) every week. At the end of this semester their GPA is recorded as well. The resulting information is categorized per student into two variables: physical activity (recorded as "above average", "average", or "below average") and that semester's GPA. The primary interest of the research project is to understand if physical activity promotes better academic performance.

-What type of study is this?

A) Observational study
B) Randomized experiment
C) Matched pairs study
D) Repeated measures study

Question 41

Use the following information for questions:
Fifty university students are randomly chosen from the college campus. Their physical fitness routines and academic performance will be assessed. They are asked to maintain a diary over a semester to record their physical activity (i.e. work-outs) every week. At the end of this semester their GPA is recorded as well. The resulting information is categorized per student into two variables: physical activity (recorded as "above average", "average", or "below average") and that semester's GPA. The primary interest of the research project is to understand if physical activity promotes better academic performance.

-Which of the following principles was used in this study?

A) Randomization
B) Control
C) Replication
D) Blinding

Question 42

Use the following information for questions:
Fifty university students are randomly chosen from the college campus. Their physical fitness routines and academic performance will be assessed. They are asked to maintain a diary over a semester to record their physical activity (i.e. work-outs) every week. At the end of this semester their GPA is recorded as well. The resulting information is categorized per student into two variables: physical activity (recorded as "above average", "average", or "below average") and that semester's GPA. The primary interest of the research project is to understand if physical activity promotes better academic performance.

-Which variable is the explanatory variable in this study?

A) The diary
B) Physical activity
C) GPA
D) Academic performance

Question 43

Use the following information for questions:
Having a coffee fix just before a workout may not be the best idea, a study suggests. Researchers in Switzerland found that the amount of caffeine in just two cups of coffee limits the body's ability to increase blood flow to the heart during exercise. The study included 18 young, healthy people who were regular coffee drinkers. They did not drink any coffee for 36 hours prior to study testing. The researchers used high-tech PET scans to measure the participants' heart blood flow before and after they rode a stationary bike and then repeated the testing procedure after swallowing a tablet containing 200 milligrams of caffeine -- the amount contained in two cups of coffee. The caffeine did not affect heart blood flow when the participants were inactive. However, measurements taken immediately after exercise showed a slowdown in heart blood flow after they'd taken the caffeine tablets, compared to their previous results.

-What type of study is this?

A) Observational study
B) Randomized block design
C) Matched pairs study
D) Repeated measures study

Question 44

Use the following information for questions:
Having a coffee fix just before a workout may not be the best idea, a study suggests. Researchers in Switzerland found that the amount of caffeine in just two cups of coffee limits the body's ability to increase blood flow to the heart during exercise. The study included 18 young, healthy people who were regular coffee drinkers. They did not drink any coffee for 36 hours prior to study testing. The researchers used high-tech PET scans to measure the participants' heart blood flow before and after they rode a stationary bike and then repeated the testing procedure after swallowing a tablet containing 200 milligrams of caffeine -- the amount contained in two cups of coffee. The caffeine did not affect heart blood flow when the participants were inactive. However, measurements taken immediately after exercise showed a slowdown in heart blood flow after they'd taken the caffeine tablets, compared to their previous results.

-Which variable is an explanatory variable in this study?

A) The health of the participants
B) Taking a caffeine tablet (yes or no)
C) Difference in heart blood flow
D) The PET scan

Question 45

Use the following information for questions:
Having a coffee fix just before a workout may not be the best idea, a study suggests. Researchers in Switzerland found that the amount of caffeine in just two cups of coffee limits the body's ability to increase blood flow to the heart during exercise. The study included 18 young, healthy people who were regular coffee drinkers. They did not drink any coffee for 36 hours prior to study testing. The researchers used high-tech PET scans to measure the participants' heart blood flow before and after they rode a stationary bike and then repeated the testing procedure after swallowing a tablet containing 200 milligrams of caffeine -- the amount contained in two cups of coffee. The caffeine did not affect heart blood flow when the participants were inactive. However, measurements taken immediately after exercise showed a slowdown in heart blood flow after they'd taken the caffeine tablets, compared to their previous results.

-Which variable is the response variable in this study?

A) Caffeine content
B) Physical activity (stationary bike)
C) Difference in heart blood flow
D) Taking a caffeine tablet (yes or no)

Question 46

Use the following information for questions:
You wish to study the effect of a tutoring program to help improve student grades in an introductory statistics course.
-Propose an experimental study design to answer the question.

Question 47

Use the following information for questions:
You wish to study the effect of a tutoring program to help improve student grades in an introductory statistics course.
-Propose a matched-pairs study design to answer the question.

Question 48

Use the following information for questions:
A researcher designed a study to assess whether grades in a statistics course could be improved by using a new teaching technique. The 250 students enrolled in a large introductory statistics class are also enrolled in one of 20 lab sections. The 20 lab sections are randomly divided into 2 groups of 10 lab sections each. The students in the first set of 10 lab sections are taught by this "new" method. The students in the remaining 10 lab sections are taught using the "old" techniques. The grades at the end of the term are then compared. Assume that the students do not know if the method they are being taught with is the old or the new method.
-What type of study is described above? Explain your answer.

Question 49

Use the following information for questions:
A researcher designed a study to assess whether grades in a statistics course could be improved by using a new teaching technique. The 250 students enrolled in a large introductory statistics class are also enrolled in one of 20 lab sections. The 20 lab sections are randomly divided into 2 groups of 10 lab sections each. The students in the first set of 10 lab sections are taught by this "new" method. The students in the remaining 10 lab sections are taught using the "old" techniques. The grades at the end of the term are then compared. Assume that the students do not know if the method they are being taught with is the old or the new method.
-Identify the explanatory variable and the response variable in this study.

Question 50

Use the following information for questions:
A researcher designed a study to assess whether grades in a statistics course could be improved by using a new teaching technique. The 250 students enrolled in a large introductory statistics class are also enrolled in one of 20 lab sections. The 20 lab sections are randomly divided into 2 groups of 10 lab sections each. The students in the first set of 10 lab sections are taught by this "new" method. The students in the remaining 10 lab sections are taught using the "old" techniques. The grades at the end of the term are then compared. Assume that the students do not know if the method they are being taught with is the old or the new method.
-Suppose the students in the "new" group were mostly upper-classmen and the students in the "old" group were mostly first and second-year students. What is the statistical name for the variable "year in school" in this study?

Question 51

A case-control study found higher exposure to gases, dusts, and fumes in the workplace among patients with bronchitis (an inflammation of the lungs) than among patients without bronchitis. What type of study is this?

A) Retrospective
B) Prospective

Question 52

A sample of 16,000 women was randomly assigned to take HRT (Hormone Replacement Therapy) or a placebo for 8 years. The results found a larger proportion of heart attacks among women taking HRT than placebo. What type of study is this?

A) Retrospective
B) Prospective

Question 53

A difficult birth may put a baby at greater risk for autism, according to a study that may provide clues to the causes of the devastating neurological disability. The Centers for Disease Control and Prevention said that in a study of 698 Danish children who had the developmental disorder (autism), researchers found a disproportionately high number had been born before the 35^th week of pregnancy, had suffered from low birth weights and were in a breech position at birth. What type of study is this?

A) Retrospective
B) Prospective

Question 54

A tea manufacturer is trying to decide whether to add peach flavoring or mango flavoring to green tea for a new product. A study is done by stopping customers at a grocery store and asking them to drink a small cup of tea with each flavoring, then to rate each of the two flavors on a scale from 1 to 10. The order in which the teas are presented is randomly assigned for each person. What type of study is this?

A) An observational study.
B) A sample survey.
C) A case-control study.
D) A matched-pairs design.

Question 55

A researcher randomly sampled 100 students at a university and asked them if they regularly take vitamins. He also asked them how many colds they had in the last six months. He then compared the number of colds experienced by those who take vitamins to the number of colds experienced by those who don't take vitamins. What type of study is this?

A) Observational study
B) Case control study
C) Matched pairs study
D) Randomized experiment

Question 56

In a study of acupuncture for treating pain 100 patients were recruited. Half were randomly assigned to receive acupuncture and the other half to receive a sham acupuncture treatment. The patients were followed for 6 months and the degree of pain relief measured. The patients did not know which treatment they actually received, but the treating physicians were aware of who was getting acupuncture and who wasn't. Which of the following does not apply to this study?

A) Randomized Experiment
B) Retrospective Study
C) Placebo Control
D) Single Blind

Question 57

In a study of 62,641 female nurses the amount of selenium in toenail clippings was measured, and then they were followed for a number of years to determine the risk of cancer. Which of the following applies to this study?

A) Randomized Experiment
B) Prospective Study
C) Placebo Control
D) Single Blind

Question 58

A group of 709 patients with lung cancer was compared to a group of 709 controls. For each patient with lung cancer, a control patient from the same hospital and the same sex and age as the lung cancer patient was selected. The two groups were compared on their smoking habits. Which of the following applies to this study?

A) Randomized Experiment
B) Prospective Study
C) Case-control Study
D) Placebo Control

Question 59

A large international trial recruited 7,000 healthy women and randomly assigned them to receive either tamoxifen or a placebo. The women were followed for a number of years and the breast cancer rates were compared between the two groups. Neither the women nor the treating physicians knew which treatment the women were actually receiving. Which of the following does not apply to this study?

A) Randomized Experiment
B) Case-control study
C) Placebo Control
D) Double Blind

Question 60

In a Gallup telephone survey of 1001 adults done before the Thanksgiving holiday, 58% said they would like to lose a few pounds. Which of the following applies to this study?

A) Randomized Experiment
B) Observational Study
C) Single Blind
D) Double Blind

Question 61

Use the following information for questions:
A difficult birth or a history of mental illness in a parent may put a baby at greater risk for autism. The Centers for Disease Control and Prevention said that in a study of 698 Danish children with the developmental disorder, researchers found a disproportionately high number had been born before the 35th week of pregnancy, had suffered from low birth weights and were in a breech position at birth. The children, all of whom were born after 1972 and diagnosed with autism before 2000, also were more likely to have a parent who had been diagnosed with schizophrenia-like psychosis before the autism was discovered.

-What type of study is this?

A) A prospective observational study
B) A retrospective observational study
C) A case-control study
D) An experiment

Question 62

Use the following information for questions:
A difficult birth or a history of mental illness in a parent may put a baby at greater risk for autism. The Centers for Disease Control and Prevention said that in a study of 698 Danish children with the developmental disorder, researchers found a disproportionately high number had been born before the 35th week of pregnancy, had suffered from low birth weights and were in a breech position at birth. The children, all of whom were born after 1972 and diagnosed with autism before 2000, also were more likely to have a parent who had been diagnosed with schizophrenia-like psychosis before the autism was discovered.

-What is the response variable in this study?

A) time of birth (before or after week 35)
B) birth weight (low or normal)
C) birth position (breech or normal)
D) presence of autism

Question 63

Use the following information for questions:
A difficult birth or a history of mental illness in a parent may put a baby at greater risk for autism. The Centers for Disease Control and Prevention said that in a study of 698 Danish children with the developmental disorder, researchers found a disproportionately high number had been born before the 35th week of pregnancy, had suffered from low birth weights and were in a breech position at birth. The children, all of whom were born after 1972 and diagnosed with autism before 2000, also were more likely to have a parent who had been diagnosed with schizophrenia-like psychosis before the autism was discovered.

-Which of the following applies to this study?

A) Randomization
B) Placebo Control
C) Blinding
D) None of the above

Question 64

Use the following information for questions:
Very young children who live in homes where the television is on most of the time may have more trouble learning how to read than other kids their age, according to a study of media habits of children up to 6 years old. The report, based on a survey of parents, also found that kids in the 6 months to 6-year-old age group spend about two hours a day watching television, playing a video game or using a computer. That's roughly the same amount of time they spend playing outdoors and three times as long as they spend reading or being read to.

-What type of study is this?

A) A prospective observational study
B) A retrospective observational study
C) Case-control study
D) An experiment

Question 65

Use the following information for questions:
Very young children who live in homes where the television is on most of the time may have more trouble learning how to read than other kids their age, according to a study of media habits of children up to 6 years old. The report, based on a survey of parents, also found that kids in the 6 months to 6-year-old age group spend about two hours a day watching television, playing a video game or using a computer. That's roughly the same amount of time they spend playing outdoors and three times as long as they spend reading or being read to.

-What is the response variable in this study?

A) Age of the child
B) Ability to learn how to read
C) Time spent playing outside
D) Television habits in the home

Question 66

Use the following information for questions:
Very young children who live in homes where the television is on most of the time may have more trouble learning how to read than other kids their age, according to a study of media habits of children up to 6 years old. The report, based on a survey of parents, also found that kids in the 6 months to 6-year-old age group spend about two hours a day watching television, playing a video game or using a computer. That's roughly the same amount of time they spend playing outdoors and three times as long as they spend reading or being read to.

-Which of the following applies to this study?

A) Randomization
B) Placebo Control
C) Blinding
D) None of the above

Question 67

You wish to study the effect of a tutoring program to help improve student grades in an introductory statistics course. Propose a retrospective study design to answer the question.

Question 68

You wish to study the effect of a tutoring program to help improve student grades in an introductory statistics course. Propose a prospective study design to answer the question.

Question 69

A distortion of results caused by the response of subjects to the special attention they receive from researchers is called

A) extending results inappropriately.
B) relying on memory or second hand sources.
C) a cause and effect relationship.
D) a Hawthorne Effect.

Question 70

When the results of a study on adults is applied to children, the effect is called

A) extending results inappropriately.
B) relying on memory or second hand sources.
C) a cause and effect relationship.
D) a Hawthorne Effect.

Question 71

When subjects receive subtle cues from the researchers about what outcomes are expected, the effect is called

A) extending results inappropriately.
B) relying on memory or second hand sources.
C) a Hawthorne Effect.
D) an Experimenter Effect.

Question 72

A survey of 1,204 black respondents found that 31% agreed with the statement "American society is fair to everyone" when the race of the interviewer was white, but only 14% agreed when the race of the interviewer was black. The difference between these responses is an example of

A) extending results inappropriately.
B) relying on memory or second hand sources.
C) a Hawthorne Effect.
D) an Experimenter Effect.

Question 73

Use the following information for questions:
For each relationship, decide whether the variable is an interacting variable or a confounding variable.

-Nicotine patches have been shown to be effective in getting smokers to quit smoking. The therapy is even more effective when there are no other smokers in the home. The absence of other smokers in the home is

A) a potential confounding variable.
B) an interacting variable.

Question 74

Use the following information for questions:
For each relationship, decide whether the variable is an interacting variable or a confounding variable.

-The greater the hours of television watched, the lower the GPA (grade point average). The number of units (credit hours) taken is

A) a potential confounding variable.
B) an interacting variable.

Question 75

Use the following information for questions:
For each relationship, decide whether the variable is an interacting variable or a confounding variable.

-Suppose that a public television station found that the amount of donations following a promotional show was larger for women than for men. Gender is

A) a potential confounding variable.
B) an interacting variable.

Question 76

Use the following information for questions:
For each relationship, decide whether the variable is an interacting variable or a confounding variable.

-The effect of a pain relief medicine was much less if the user was under 50. Age is

A) a potential confounding variable.
B) an interacting variable.

Question 77

Use the following information for questions:
For each relationship, decide whether the variable is an interacting variable or a confounding variable.

-A professor found an association between the number of times a student came to office hours and the grade received in the course. The total number of hours that a student studied in the course is

A) a potential confounding variable.
B) an interacting variable.

Question 78

Use the following information for questions:
Researchers would like to compare meditation and exercise to see which is more effective for reducing stress. One hundred people who suffer from high stress volunteer to participate in a study for ten weeks. Participants will either be given a 10-week course in meditation or will participate in a 10-week exercise program. The researchers must decide whether to randomly assign the volunteers to the two programs, or allow them to choose.

-Which of the following is the main advantage of randomly assigning participants to the two programs rather than allowing them to choose?

A) The participants are more likely to stick with the program for the full 10 weeks.
B) Confounding variables, such as past practice of meditation, should be approximately equal for the two groups.
C) Random assignment ensures that the two sample sizes are equal and that requirement is necessary in studies like this one.
D) Random assignment will allow the results to be extended to the population of all adults.

Question 79

Use the following information for questions:
Researchers would like to compare meditation and exercise to see which is more effective for reducing stress. One hundred people who suffer from high stress volunteer to participate in a study for ten weeks. Participants will either be given a 10-week course in meditation or will participate in a 10-week exercise program. The researchers must decide whether to randomly assign the volunteers to the two programs, or allow them to choose.

-Which of the following is an advantage of allowing participants to choose the program in which to participate?

A) Allowing them to choose will increase the ecological validity of the study because in the real world people choose their own programs.
B) Confounding variables, such as past practice of meditation, should be approximately equal for the two groups.
C) Allowing participants to choose will allow the results to be extended to the population of all adults.
D) If participants are allowed to choose then a cause and effect conclusion can be made.

Question 80

Use the following information for questions:
Researchers would like to compare meditation and exercise to see which is more effective for reducing stress. One hundred people who suffer from high stress volunteer to participate in a study for ten weeks. Participants will either be given a 10-week course in meditation or will participate in a 10-week exercise program. The researchers must decide whether to randomly assign the volunteers to the two programs, or allow them to choose.

-Suppose participants are randomly assigned to the two programs and a psychologist measures their stress levels before and after the 10-week program, without being told who is in which program. This experiment would be

A) Single blind as long as the participants are not told the results of the stress level measurements.
B) Single blind because the psychologist doesn't know who is in which program, but the participants do know.
C) Double blind as long as the participants are not told the results of the stress level measurements.
D) Neither single nor double blind.