AMMO CDC Module 6 Practice Test

Statistical significance shows whether an observed association is unlikely to be due to random variation, but it doesn't tell you how big or important the effect is in real-world terms. A small effect can still produce a p-value below 0.05 if the study has a large sample, so the result is statistically significant even though the actual difference would have little public health impact. This is why significance alone doesn’t imply a large or meaningful impact. It also doesn’t prove causation, since a low p-value only speaks to probability under the null hypothesis, not cause-and-effect. In short, you can have a statistically significant result with a tiny, potentially trivial effect size, so practical significance must be considered separately from statistical significance.