A Researcher Administers an Antidepressant Drug to a Group of Depressed

Multiple Choice

A researcher administers an antidepressant drug to a group of depressed patients and over a period of time they improve. The researcher claims that their improvement is due to
The drug, even though she did not control for outside factors such as improved emotional
Support from friends, or natural improvement over time. This study lacks ______.

A) analogue validity
B) construct validity
C) internal validity
D) external validity