In an experiment, it is essential that A) the group sizes are ...

[dbose]

In an experiment, it is essential that
 
  A) the group sizes are equal.
  B) the experimental and control groups are comparable at the start of the study.
  C) all participants are given a pretest.
  D) the groups are equal after the manipulation.

Question 2

Which of the following is essential for a successful control-group design?
 
  A) that the experimental and control groups be comparable at the start of the study
  B) that participants be randomly selected from a general population
  C) that at least three conditions are manipulated
  D) that there be an equal number of male and female participants

[yotaSR5]

Answer to Question 1

Answer: B

Answer to Question 2

Answer: A