An important reason for using random assignment in a study with ...

[jrubin]

An important reason for using random assignment in a study with independent groups is to
 
  a. prevent any systematic differences between groups on extraneous variables.
  b. be able to generalize to broader populations.
  c. rule out competing interpretations of any differences we find.
  d. a and c

Question 2

If we built on Doob and Gross's study of horn-honking behavior to compare the time it takes for people to honk at an older car versus the time to honk at an expensive newer car, we could set it up as
 
  a. an independent sample design.
  b. a repeated measures design.
  c. neither a nor b
  d. It could be designed either way, depending upon our needs.

[lkanara2]

Answer to Question 1

D

Answer to Question 2

D