The school newspaper reports that the GPA of athletes is slightly ...

[nenivikky]

The school newspaper reports that the GPA of athletes is slightly higher than the GPA of undergraduates in general. Suppose you want to use these data to argue that athletes are smarter than the average student. Someone else points out that intelligence (smartness) is only one of several factors influencing GPA; others are self-discipline, tutoring, pressure from coaches, required class attendance, and so on. Each of these latter factors is a potential ____ in any simple explanation of GPA.
 
  a. exogenous variable
  b. moderator variable
  c. placebo
  d. confounding variable
  e. discriminant variable

Question 2

A researcher who wants to conduct a study in the local high school finds that she must use volunteers rather than intact class groups. In this case, the researcher should
 
  a. make sure to use a sample of at least 30 or more subjects.
  b. control for the subjects' willingness to volunteer.
  c. keep the volunteer subjects naive as to the purpose of the study.
  d. determine the extent to which volunteers may differ from nonvolunteers on important variables.

[234sdffa]

Answer to Question 1

D

Answer to Question 2

D