Exam 11: More on Experiments: Confounding and Obscuring Variables

RESEARCH STUDY 11.1: In previous studies, Dr.Schulenberg has established that finding meaning in one's everyday work activities can lead to greater success in the workplace (e.g., productivity, creativity).He is curious as to whether this can happen in the college classroom.Specifically, he is curious whether finding meaning in one's classroom experience can lead to greater academic performance.In the spring semester, he has his teaching assistant randomly assign half the class to write a paragraph each class period about how the material has meaning for their lives (meaning group).The other half writes a paragraph about what they did to prepare for class (preparation group).He does not know which of his students are writing which paragraph, and the students are not aware they are responding to different writing assignments.To measure academic performance, he gives the students a midterm essay exam and a final exam. The study described above is an example of which of the following?

Dr.LaGuardia is curious as to whether children in a daycare center will share more after watching an educational video on sharing.Immediately before and after the video, he has several undergraduate research assistants code the sharing behavior of a group of 33 four-year-olds.Which of the following would you recommend to him to decrease the threat of instrumentation?

RESEARCH STUDY 11.1: In previous studies, Dr.Schulenberg has established that finding meaning in one's everyday work activities can lead to greater success in the workplace (e.g., productivity, creativity).He is curious as to whether this can happen in the college classroom.Specifically, he is curious whether finding meaning in one's classroom experience can lead to greater academic performance.In the spring semester, he has his teaching assistant randomly assign half the class to write a paragraph each class period about how the material has meaning for their lives (meaning group).The other half writes a paragraph about what they did to prepare for class (preparation group).He does not know which of his students are writing which paragraph, and the students are not aware they are responding to different writing assignments.To measure academic performance, he gives the students a midterm essay exam and a final exam. Imagine that in Dr.Schulenberg's study, he notes that all of the students do extremely well on the midterm exam.When he looks at the results of the final exam, he notices that all the students' exam scores went down.Which of the following pattern of results would suggest that there is a threat to internal validity?

Which of the following things can be done to reduce the effect of individual differences?