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. They conduct a quasi-experimental study in which they examine 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. They find 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. Which of the following makes Dr. LaGuardia’s quasi-experimental study different from a correlational study?

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

What is an example of far transfer?

What does ‘this study has a statistical power of 0.8’ mean?

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 partner 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 having W. J. record only 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.?

Adding multiple measurements before and after an experimental manipulation CANNOT eliminate which threat?

When a researcher is in theory-testing mode, __________ is/are a high priority.

RESEARCH STUDY 10.2: Dr. Dormeur studies sleep and sleep disorders. She is curious as to whether technology exposure before bedtime causes people to fall asleep more slowly. She recruits a sample of 60 middle-aged women from a local church who reported no history of sleep problems. She creates three conditions. All participants come to the sleep lab for three nights in a row and experience all three conditions. In the first condition (A), participants were asked to play an online game (Candy Crush) on an iPad for 10 minutes prior to going to bed. In the second condition (B), participants were asked to read an article using an iPad that discussed tricks and tips for improving one’s score on Candy Crush (which took about 10 minutes). In the third condition (C), participants were asked to read a newspaper article about the inventor of Candy Crush (which took about 10 minutes). With the use of an electroencephalograph (EEG), the researcher measures how long it takes participants to fall asleep. Dr. Dormeur was concerned that asking participants how long it took them to fall asleep would lead them to suspect that was the purpose of the study. Her decision to measure how long it took participants to go to sleep using the EEG instead of self-report was meant to decrease which of the following?

Individual differences are something that we want to minimize in ______

Which is NOT a potential internal validity threat in any study?