An experiment is conducted to test the effectiveness of a social work intervention. The experimental group improves more than does the control group, but the results are not statistically significant. This means that
A) the intervention was not effective.
B) the intervention was effective, but not at a significant level.
C) we cannot rule out sampling error in inferring about the effectiveness of the intervention.
D) the results were clinically significant despite not being statistically significant.

Question

An experiment is conducted to test the effectiveness of a social work intervention. The experimental group improves more than does the control group, but the results are not statistically significant. This means that​
A) ​the intervention was not effective.
B) ​the intervention was effective, but not at a significant level.
C) ​we cannot rule out sampling error in inferring about the effectiveness of the intervention.
D) ​the results were clinically significant despite not being statistically significant.

Quizplus · Accepted Answer

This means that although the experimental group improved more than the control group, the difference was not large enough to confidently conclude that the intervention was effective. The lack of statistical significance indicates that there is a possibility that the results were due to chance or sampling error, and that further research may be necessary to confirm the effectiveness of the intervention.

An Experiment Is Conducted to Test the Effectiveness of a Social