A researcher states in an article, "The subjects acted as their own controls." If this is true, it implies which of the following? (Select all that apply.)

Question

a. The result measured by the researchers was something that varies more from person to person than it does within a single person.
b. There were so few subjects that a separate control group could not be obtained.
c. Measurement of the subjects was made at least twice.
d. Two studies were performed.
e. The methodology was quasi-experimental.
f. The study was interventional.

Answer 1

ANS: A, C, E, F
The rationale for using a design in which subjects act as their own controls is that whatever is being measured varies quite a bit between persons, and the researcher is more interested in showing a change in the subjects than producing a given number value; because of this, a separate control group makes little sense. Examples of this are pain, nausea, and panic. If subjects act as their own controls, they must be measured at least once in the control condition and at least once in the experimental condition. Experimental research requires a separate control group; some quasi-experimental research allows subjects to act as their own controls. Correlational and descriptive research does not use controls—it uses comparison subjects. Quasi-experimental research is interventional.