After applying a statistical test, an investigator gets the &;p value&; as 0.01. It means that-
**Core Concept**
The p-value is a statistical measure used to determine the probability of observing the results of a study by chance, assuming that the null hypothesis is true. In essence, it's a measure of the likelihood of obtaining the observed results (or more extreme) if there's no real effect or association.
**Why the Correct Answer is Right**
A p-value of 0.01 indicates that if the null hypothesis is true, there's only a 1% chance of observing the study results (or more extreme) by chance. This low p-value suggests that the results are statistically significant, implying that the observed effect or association is unlikely to be due to chance. In this context, the investigator can reject the null hypothesis and conclude that there's a statistically significant difference or association.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the p-value doesn't directly indicate the strength or magnitude of the effect; it merely suggests whether the result is statistically significant or not.
**Option B:** This option is incorrect because a p-value of 0.01 doesn't imply that the observed effect is due to a single, specific cause; it only suggests that the result is unlikely to be due to chance.
**Option C:** This option is incorrect because a p-value of 0.01 doesn't necessarily mean that the study has a high predictive power or that the results can be reliably replicated.
**Clinical Pearl / High-Yield Fact**
When interpreting p-values, remember that a p-value of 0.05 is often considered the threshold for statistical significance, but this value can be misleading. A p-value of 0.01 or lower is generally more convincing evidence of a statistically significant effect.
**Correct Answer:** C.