Exam 13: Quasi-Experiments and Small-N Designs

Which of the following people would be of most interest for a small-N design?

RESEARCH STUDY 13.1: 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.This type of design is known as a(n):

RESEARCH STUDY 13.3: 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.?

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

RESEARCH STUDY 13.3: 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 statistical validity of Dr.Anderson's study, which of the following might be asked?

RESEARCH STUDY 13.2: 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 interrogating the construct validity of Dr.LaGuardia's study, which of the following statements is accurate?

RESEARCH STUDY 13.1: 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?

RESEARCH STUDY 13.4: Dr.Fletcher is interested in understanding 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, where higher scores indicate higher body concerns). Explain why Dr.Fletcher is conducting a quasi-experimental design rather than a true experiment.

RESEARCH STUDY 13.3: 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. Dr.Natchez, a colleague of Dr.Anderson, questions whether W.J.simply wrote down less in his journal as the study went on because he grew tired of completing this "measure." Dr.Natchez believes he has uncovered which of the following threats to internal validity?

In small-N designs, each participant is treated:

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

RESEARCH STUDY 13.2: 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. If Dr.LaGuardia had instead been interested in conducting a small-N design, which of the following might he have done?

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.

Which of the following CANNOT typically be applied to a small-N experiment?

A wait-list design is helpful in dealing with which of the following threats to internal validity?

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

RESEARCH STUDY 13.1: 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 would be able to better address which of the following threats to internal validity?

RESEARCH STUDY 13.1: 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 finds that joining a fraternity/sorority reduces self-esteem about one's appearance.Who could his study generalize to?

RESEARCH STUDY 13.3: 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?

Which of the following is a difference between true experiments and quasi-experiments?