In a true experiment, the researcher _______ variables, and in a quasi-experiment the researcher ...

In a true experiment, the researcher _______ variables, and in a quasi-experiment the researcher _______ variables.
 
  a. manipulates, observes
  b. observes manipulates
  c. controls, assigns
  d. assigns, records

Question 2

If an experiment compared preexisting classes of students, the two classes would be called
 
  a. Ex post facto variables
  b. Extraneous variables
  c. Confounding variables
  d. Dependent variables

Question 3

Which of the following is a subject variable?
 
  a. sex of participant
  b. number of trials
  c. friendly versus formal treatment by experimenter
  d. reaction time