Dr. Zink and Dr. Vasquez are designing a new study. They have come up with a good hypothesis for the study, but they are having trouble thinking of operational definitions for their variables. In other words, they are concerned that their research might be low in ____.

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

Construct validity refers to how well a test or experiment measures up to its claims. If Dr. Zink and Dr. Vasquez are struggling with operational definitions for their variables, it means they might have difficulty ensuring that their study accurately assesses the theoretical constructs they're interested in, thus affecting the study's construct validity.