Exam 6: Gathering Useful Data for Examining Relationships

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

Use the following information for questions: A researcher wishes to see whether there is any difference in the average weight gains of athletes following one of three special diets (Diet 1, Diet 2, and Diet 3). The initial study design was to randomly assign the athletes to one of the three diet groups and place them on the diet for six weeks. The weight gain (in pounds) at the end of the six weeks would be recorded for each athlete. -What type of study is this?

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

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

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.

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.

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?

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.

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

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

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?

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.

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

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.

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?

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?

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.

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?

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.

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?