In which of the following situations is a reasonable experiment unable to be designed?

An experiment is futile if there is no clear way to measure the data to draw a conclusion. A conclusion cannot be made without evidence of some kind either quantitative or qualitative or both. In some cases, as is true for sociological studies, the data collected may only be qualitative, which is still appropriate to be able to draw a conclusion. The same is true for experiments that are heavy in quantitative evidence.[Scientific Reasoning]