What is the PRIMARY distinction between a pre-experimental, quasi-experimental, and experimental research design?
Group of answer choices
a. Whether the study includes a pre-test
b. Whether the study design includes a comparison or control group
c. The extent to which the sampling strategy involves probability vs. non-probability sampling.
d. The extent to which the design addresses threats to internal validity.
e. Whether or not the study involves a program evaluation or not.
