Exam 13: Quasi-Experiments and Small-N Designs

Dr. Anderson is a nutritionist who helps clients lose weight prior to surgery. She is working with W. J., a male client who is planning on undergoing a heart transplant. He currently eats more than 3,500 calories a day and has been asked by his doctor to cut the number of calories to about 1,800 (400 for breakfast, 600 for lunch, and 800 for dinner). She is curious as to whether a food journal will help W. J. reduce the number of calories he eats. A food journal is used to record everything a person eats to help patients be more aware of what they're eating. W. J.'s wife also recorded the food he consumed at each meal to have complete data before introducing the journal. Dr. Anderson decides to phase in the food journal gradually, initially only having W. J. record what he ate at breakfast during the first three days after baseline (days 4-6). During days 7-9, the journal is used at lunch, too, and during days 10-12, it also is used during dinner. The data for Dr. Anderson's study are below. In interrogating the construct validity of Dr. Anderson's study, which of the following might be asked?

In conducting quasi-experimental designs, researchers tend to give up some in exchange for .

In quasi-experimental designs, the researcher does not have experimental control over the independent variable and does not randomly assign participants to conditions. This results in which of the following?

According to the textbook, which of the following ethical questions might be posed specifically in reference to a reversal design?

List three small-N designs and explain how these designs address maturation.

The degree to which a quasi-experiment supports a causal claim depends on which of the following?

Which of the following is an advantage of using quasi-experimental designs?

Which of the following topics would be especially well suited to a quasi-experimental design?

Which of the following is a difference between small-N and large-N designs?

Lara is conducting a study for her research methods class. She is curious if participating in a collegiate study-abroad program causes people to become more accepting of other cultures. Provide an example of an independent-groups quasi-experimental design and an example of a within-groups quasi-experimental design using Lara's research question.

Dr. Anderson is a nutritionist who helps clients lose weight prior to surgery. She is working with W. J., a male client who is planning on undergoing a heart transplant. He currently eats more than 3,500 calories a day and has been asked by his doctor to cut the number of calories to about 1,800 (400 for breakfast, 600 for lunch, and 800 for dinner). She is curious as to whether a food journal will help W. J. reduce the number of calories he eats. A food journal is used to record everything a person eats to help patients be more aware of what they're eating. W. J.'s wife also recorded the food he consumed at each meal to have complete data before introducing the journal. Dr. Anderson decides to phase in the food journal gradually, initially only having W. J. record what he ate at breakfast during the first three days after baseline (days 4-6). During days 7-9, the journal is used at lunch, too, and during days 10-12, it also is used during dinner. The data for Dr. Anderson's study are below. Which of the following aspects of Dr. Anderson's study might be susceptible to observer bias?

Dr. Fletcher is interested in whether joining a fraternity/sorority causes people to become more concerned about their attractiveness and appearance. He recruits a group of 55 freshmen (25 males, 30 females) who are planning to go through fraternity/sorority recruitment on his campus. After they join, he gives them a measure of attractiveness concern/appearance concern (the Body Concern Scale). In addition to measuring the Body Concern of the participants who joined a fraternity/sorority both immediately before and immediately after they join, Dr. Fletcher measures them for the 3 weeks before and the 3 weeks after. This type of design is known as a(n):

Which of the following is NOT a small-N design?

Dr. Fletcher is interested in whether joining a fraternity/sorority causes people to become more concerned about their attractiveness and appearance. He recruits a group of 55 freshmen (25 males, 30 females) who are planning to go through fraternity/sorority recruitment on his campus. After they join, he gives them a measure of attractiveness concern/appearance concern (the Body Concern Scale). Suppose Dr. Fletcher was concerned that students who choose to join fraternities/sororities are more concerned with their appearance overall. How could he test whether this type of selection threat exists?

Layne is trying to watch less television. Her friend Ryan is a psychologist who agrees to help her. He creates a treatment plan that involves giving Layne $5 for every day that she watches fewer than 90 minutes of television. He monitors her television watching for 3 days, treats her for 3 days and monitors her, and then just monitors her for 3 more days. What type of design is Ryan using to change Layne's behavior? Name a threat to internal validity that this design is well suited to address.

Dr. LaGuardia is a cognitive neuroscientist who is interested in the effect of brain concussions on the ability to recognize faces. He conducts a quasi-experimental study in which he examines football players before and after the regular season using the Benton Facial Recognition Test (a published, widely used measure of one's ability to recognize faces) to compare those who received concussions to those who did not. He finds that players who had concussions during the regular season performed worse on the Benton Facial Recognition Test than did players who did not experience concussions. In analyzing the data, Dr. LaGuardia finds that there was no pretest difference in Benton Facial Recognition scores. However, he does find that the football players who received concussions had worse visuo-spatial awareness before the study. Which of the following threats to internal validity should he be concerned with?

List the three differences between small-N and large-N designs.

Dr. Fletcher is interested in whether joining a fraternity/sorority causes people to become more concerned about their attractiveness and appearance. He recruits a group of 55 freshmen (25 males, 30 females) who are planning to go through fraternity/sorority recruitment on his campus. After they join, he gives them a measure of attractiveness concern/appearance concern (the Body Concern Scale). In addition to measuring the group of participants who joined a fraternity/sorority, Dr. Fletcher decides to give the same measure to another group of 55 participants who decided to not join a fraternity/sorority. Doing this would help Dr. Fletcher address all of the following threats to internal validity EXCEPT:

Explain why quasi-experiments and correlational studies can be seen as similar but why quasi-experiments are superior.

Dr. Anderson is a nutritionist who helps clients lose weight prior to surgery. She is working with W. J., a male client who is planning on undergoing a heart transplant. He currently eats more than 3,500 calories a day and has been asked by his doctor to cut the number of calories to about 1,800 (400 for breakfast, 600 for lunch, and 800 for dinner). She is curious as to whether a food journal will help W. J. reduce the number of calories he eats. A food journal is used to record everything a person eats to help patients be more aware of what they're eating. W. J.'s wife also recorded the food he consumed at each meal to have complete data before introducing the journal. Dr. Anderson decides to phase in the food journal gradually, initially only having W. J. record what he ate at breakfast during the first three days after baseline (days 4-6). During days 7-9, the journal is used at lunch, too, and during days 10-12, it also is used during dinner. The data for Dr. Anderson's study are below. What type of small-N design has Dr. Anderson used with W. J.?