When a finding is statistically significant:

When a finding is statistically significant:
 
  A) alternative explanations other than the independent variable are not plausible.
 B) a strong relationship has been observed.
 C) it is an important finding.
 D) its meaning depends on the rigor of the research methods.

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In an evaluation of an intervention that seeks to reduce depression scores among the frail elderly, the mean of the experimental group is 30, the mean of the control group is 60, and the standard deviation is 10. Cohen's d effect size is
 
  A) 3
 B) minus 3
 C) 30
 D) 10

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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.