An Experiment Is Conducted to Test the Effectiveness of a Social

Multiple Choice

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.