The one-group posttest-only design should be avoided because
a. All experimental designs have to have more than one group
b. There are many uncontrolled threats to validity
c. It produces unreliable results
d. It will not be possible to code the data
Question 2
You decide that you want to see whether a popular motivational program Optimize Your Life actually works. You survey the participants after they have taken part in the study. This experimental design is called a
a. Single-factor within-subjects
b. Single-factor between subjects
c. One-group pretest-posttest
d. One-group posttest-only design