Which of the following best describes a pre-test/post-test study?

A pre-test/post-test study is best described as a related sample measured before and after an intervention because it focuses on comparing the same group of participants at two different points in time. This design allows researchers to assess the effect of a specific intervention by measuring some variable before the intervention (the pre-test) and then measuring the same variable after the intervention (the post-test). This approach is particularly useful in understanding changes over time that can be attributed to the intervention itself, providing insights into effectiveness and causal relationships.

In contrast, a method that subjects participants to two different variables does not capture the idea of measuring the same group before and after an intervention. A research design with subjects that are unrelated does not fit the pre-test/post-test format because it requires the same subjects for both measurements. Lastly, a control study with no associated independent variable fails to encompass the concept of measuring outcomes in relation to an intervention, which is a fundamental aspect of the pre-test/post-test methodology.