With regard to external validity, what is the main problem with ...

[rosent76]

With regard to external validity, what is the main problem with only using undergraduate
  psychology students in psychological research?
 
  A) Results may be biased because most students do research to earn money or extra credit.
  B) Results may not apply to a larger group of people because students are different from
  other people in the United States and around the world.
  C) Results may not apply to a larger group of people because it is not a random sample.
  D) Results may be biased because there are more women in psychology than men.

Question 2

The assumption of parametric tests of significance that the variances of the populations are
  equivalent is called
 
  A) homogeneity of variance B) assumption of normality
  C) heterogeneity of variance D) equivalence of variance

[kingfahad97]

Answer to Question 1

B

Answer to Question 2

A

[rosent76]

TYSM

[amit]

Excellent