Grip strength is a common physical fitness assessment tool that is highly reliable, however research has demonstrated that it has little relationship to actual fitness levels. Which of the following best describes the use of grip strength as a measure of physical fitness?

It has low face validity.

It has low construct validity.

It has a high predictive validity.

It has high criterion validity

The correct answer is It has low construct validity.

Internal validity refers to both the good performance of the study (research design, operational definitions used, variables were measured, what was / was not measured, etc.) and how much confidence one can have that the change in the dependent variable it was produced exclusively by the independent variable and not by some strange / spurious variable.

Answer: It has low construct validity.

Explanation: Construct validity can be said to be whether a scale or test measures the construct adequately. It is "the degree to which a test measures what it claims, or purports, to be measuring."

In this question, grip strength was as a tool for measuring physical fitness but research showed that grip strength doesn't determine fitness levels therefore, this has a low construct validity. This is because using grip strength as a tool for physical fitness doesn't measure physical fitness adequately.