When comparing two population means, it is important to know if the investigation was an experiment where the researcher was able to control which subject gets what treatment, or if the study was observational. Suppose that a statistically significant result is obtained in a study. How would the interpretations of the results differ, based on whether the study was observational or the study was an experiment?

Question

Quizplus · Accepted Answer

The Answer is If a study is not such that the treatments are randomly assigned, then no causal conclusions can be made. Therefore, even if two samples or treatments have a statistically significant difference, it will not be possible to decide that the two populations are different or that the two treatments have a different effect.

When Comparing Two Population Means, It Is Important to Know