Statistics Test 1 (Chapters 9 &10)
Which of the following is not a principle of experiments? A) Randomization B) Control C) Blinding D) Replication
C) Blinding
A math professor wants to determine whether calculators affect student performance. He randomly assigns calculators to half the students in her class. The remaining half were asked to not use calculators. The final exam scores for the two groups were collected and analyzed. What kind of experiment design is this? A) Completely randomized design B) Matched pairs design C) Block design D) None of these
A
In which of the following circumstances would you allow collecting personal information without the subjects' consent? A) A government agency takes a random sample of income tax returns to obtain information on the marital status and average income of people who identify themselves as belonging to an ultraconservative political group. Only the marital status and income are recorded from the returns, not the names. B) A social psychologist attends public meetings of an ultraconservative political group to study the behavior patterns of members. C) A social psychologist pretends to be converted to membership of an ultraconservative political group and attends private meetings to study the behavior patterns of members.
A
Which of the following is an advantage of an experiment over an observational study? Choose all that applies. A) it is easy to control confounding variables because we are responsible to assign the treatments to the subjects. B) It is easy to describe how a a characteristic varies in the population. C) It is easy to study the combined effects of several different factors together. D) None of these
A & C
A large representative random sample of 6906 U.S. adults collected over 20 years showed that "parents reported higher levels of life satisfaction than nonparents," with the observed difference in life satisfaction between the two groups being statistically significant. This is an example of: A) An observational study B) A Randomized comparative experiment C) A matched pairs experiment D) None of these
A) An observational study
An Archaeologist undug and took measurements of the bones found in the remains of an ancient tribe that lived along the Judan river in the year 26BC. What type of study is this? A) Cross-sectional study B) Retrospective study C) Prospective study D) Experiment
A) Cross-sectional study
A math professor wants to determine whether supply graphing calculators to students would increase their performance in a particular course. In a given semester he gave calculators to one section of the course and to another section he did not give calculators. At the end of the semester he compared the performance of the two sections. Is this study an experiment or an observational study? A) Experiment B) Observational study C) Statistical study D) None of these
A) Experiment
A social psychologist pretends to be converted to membership of an ultraconservative political group and attends private meetings to study the behavior patterns of members. Which basic data ethics is violated? A) The institutional review board did not approve of the study B) The informed consent of the subjects is not given to the psychologist. C) The information disclosed to the psychologist is not confidential. D) None of these
B
The Community Intervention Trial for Smoking Cessation asked whether a community-wide advertising campaign would reduce smoking. The researchers located 11 pairs of communities, with each pair similar in location, size, economic status, and so on. One community in each pair was chosen at random to participate in the advertising campaign and the other was not. This is: A) An observational study B) A matched pairs design experiment C) A completely randomized experiment D) None of these
B) A matched pairs design experiment
Forty subjects are recruited in the study. Each subject recruited in the study has to drive with and without a cellphone. The drives with and without cell phone are scheduled for two different days. The two treatments (with and without cellphones) are assigned randomly as follows: On the first day, twenty subjects are randomly chosen to drive with cell phones, and the remaining twenty to drive without cell phones. The next day, those who drove without cellphones drive with cellphones and vice versa. What kind of experiment design is this? Choose the best answer. A) Completely randomized design B) Matched pairs design C) Block design D) None of these
B) Matched pairs design
Determine whether the following study is an observational study or an experiment: During the field work of a graduate student's project, she collects data from the registry of a hospital laboratory in the Savannah area. A) Experiment B) Observational study C) None of these
B) Observational study
A marketing class designs two videos advertising an expensive Mercedes sports car.They test the videos by asking fellow students to view both (in random order) and say which makes them more likely to buy the car. Mercedes should be reluctant to agree that the video favored in this study will sell more cars because: A) the study used a matched pairs design instead of a completely randomized design. B) results from students may not generalize to the older and richer customers who might buy a Mercedes. C) this is an observational study, not an experiment. D) None of these
B) Results from students may not generalize to the older and richer customers who might buy a Mercedes
A sculptor makes an inventory of all the different types of statues he has made in the last fifteen years. The list was presented to the director of a museum in the city for further analysis. What kind of observational study is this? A) Cross-sectional study B) Retrospective study C) Prospective study D) Experiment
B) Retrospective study
Determine whether the characteristic described in the following population is statistically significant or not. In a population, 80% of all new births are girls. A) The birth of girls is not significant because 20% boys are also born B) The birth of girls is significant because 80% is too large to be a result of chance C) The birth of boys is significant because 20% boys are born D) None of these
B) The birth of girls is significant because 80% is too large to be a result of chance
Adolescent obesity is a serious health risk affecting more than 5 million young people in the United States alone. Laparoscopic adjustable gastric banding has the potential to provide a safe and effective treatment. Fifty adolescents between 14 and 18 years old with a body mass index higher than 35 were recruited from the Mellbourne, Australia, community for the study. Twenty-five were randomly selected to undergo gastric banding, and the remaining 25 were assigned to a supervised lifestyle intervention program involving diet, exercise, and behavior modification. All subjects were followed for two years, and their weight loss was recorded. Determine the subjects in this study. A) The Melbourn community. B) The twenty-five that were randomly selected to undergo gastric banding, and the remaining 25 were assigned to a supervised lifestyle intervention program involving diet, exercise, and behavior modification. C) Only the twenty-five that were randomly selected to undergo gastric banding. D) There are no subjects
B) The twenty-five that were randomly selected to undergo gastric banding, and the remaining 25 were assigned to a supervised lifestyle intervention program involving diet, exercise, and behavior modification.
Which if the following is not true about a randomized comparative experiment? A) The control and treatment groups are completely randomized B) They involve groups that are biased. C) The subjects recruited are shared into two or more groups. D) The treatments are randomly assigned between the groups of the experiment
B) They involve groups that are biased.
Adolescent obesity is a serious health risk affecting more than 5 million young people in the United States alone. Laparoscopic adjustable gastric banding has the potential to provide a safe and effective treatment. Fifty adolescents between 14 and 18 years old with a body mass index higher than 35 were recruited from the Mellbourne, Australia, community for the study. Twenty-five were randomly selected to undergo gastric banding, and the remaining 25 were assigned to a supervised lifestyle intervention program involving diet, exercise, and behavior modification. All subjects were followed for two years, and their weight loss was recorded. Determine the treatment and the control groups in this study. A) Control Group: The twenty-five were randomly selected to undergo gastric banding, Treatment Group: The remaining 25 were assigned to a supervised lifestyle intervention program involving diet, exercise, and behavior modification. B) Treatment Group: The twenty-five were randomly selected to undergo gastric banding, Control Group: The remaining 25 were assigned to a supervised lifestyle intervention program involving diet, exercise, and behavior modification. C) Control Group:The fifty adolescents that were recruited in the study. Treatment Group: The remaining 25 were assigned to a supervised lifestyle intervention program involving diet, exercise, and behavior modification D) Control Group: The twenty-five were randomly selected to undergo gastric banding, Treatment Group: The fifty adolescents that were recruited in the study.
B) Treatment Group: The twenty-five were randomly selected to undergo gastric banding, Control Group: The remaining 25 were assigned to a supervised lifestyle intervention program involving diet, exercise, and behavior modification.
Men and women respond differently to advertisement. To conduct an experiment to determine the effectiveness of three different advertisements of the same product, a company manager separates men and women into different groups, and randomly display three different advertisements of a product to the different groups. The responses were collected for the different experiments and analyzed. What kind of experiment design is this? A) Completely randomized design B) Matched pairs design C) Block design D) None of these
C) Block design
A statistical study involves a data set of the different types of shoe designs by the designer Calvin Klein over the years from 1987 to 2014. What type of observational study is this? A) Cross-sectional study B) Retrospective study C) Prospective study D) Experiment
C) Prospective study
Which statement best describes confounding variables? A) They are confusing to find in an experiment B) They can influence the response of the subjects in the experiment but they are not known before the experiment is performed. C) Their effects on the subjects cannot be distinguished from one another. D) They confuse the experts conducting the experiment.
C) Their effects on the subjects cannot be distinguished from one another
In an experiment to determine whether the number of study hours students give to a course affects the performance of students in the course, several lurking variables may interfere with the response of the experiment. The response in this experiment that is measured is the final grades of the students. Which of the following can be a lurking variable to this experiment? A) The number of study hours B) The final grades of the students C) The experiment is not obvious and a waste of time. It should not be conducted D) financial situation of the students
D) Financial situation of the students
Adolescent obesity is a serious health risk affecting more than 5 million young people in the United States alone. Laparoscopic adjustable gastric banding has the potential to provide a safe and effective treatment. Fifty adolescents between 14 and 18 years old with a body mass index higher than 35 were recruited from the Melbourne, Australia, community for the study. Twenty-five were randomly selected to undergo gastric banding, and the remaining 25 were assigned to a supervised lifestyle intervention program involving diet, exercise, and behavior modification. All subjects were followed for two years, and their weight loss was recorded. What is the treatment of interest in this study? A) Assigned supervised lifestyle intervention program involving diet, exercise, and behavior modification B) regular exercise in the mornings and evening. C) Behavior modification such as staying active and eating healthy fruits. D) Gastric banding
D) Gastric banding
Which statement below explains how you would replicate an experiment? A) Repeat the experiment on the same subject B) Create a new control and treatment group C) Increase the number of treatments D) Increase the number of subjects
D) Increase the number of subjects
Which statement explains why blinding is useful in an experiment? A) To not let anyone know that an experiment is conducted. B) To reduce the bias in the control and treatment groups. C) To increase replication in the experiment. D) To reduce the bias that experts have in the experiment to force responses that are not true
D) To reduce the bias that experts have in the experiment to force responses that are not true.
