In an experiment, participants are randomly assigned to treatment conditions ____.
a. to help protect the internal validity of the study
b. to help protect the external validity of the study
c. to help protect both the internal and external validity
d. as an alternative to manipulation of variables
Question 2
In sampling notation, NCn refers to the ____.
a. number of cases in the sampling frame
b. number of cases in the sample
c. number of possible subsets
d. sampling fraction