The importance of p-values in statistics
03/01/2024 | by Patrick Fischer, M.Sc., Founder & Data Scientist: FDS
Significance of p-Values in Statistical Hypothesis Testing
The p-value (significance level) is a crucial concept in statistical hypothesis testing. It indicates how likely it is to observe the data given that the null hypothesis is true. A low p-value suggests that the observed data is unlikely under the assumption of the null hypothesis.
Interpretation of p-Values:
- p-Value < 0.05: In many scientific disciplines, a p-value less than 0.05 is considered statistically significant. This indicates that there is sufficient evidence to reject the null hypothesis with a certain level of confidence.
- p-Value > 0.05: A p-value greater than 0.05 usually does not lead to the rejection of the null hypothesis. The data does not provide enough evidence to reject the null hypothesis.
- Small p-Value: A very small p-value (e.g., p < 0.01) suggests that the observed data is highly unlikely under the null hypothesis. This is interpreted as strong evidence against the null hypothesis.
- Larger p-Value: A larger p-value (e.g., 0.1) indicates that the observed data is less inconsistent with the null hypothesis. However, it does not necessarily confirm the null hypothesis.
Caution:
It is important to note that a non-significant p-value does not constitute evidence in favor of the null hypothesis. The absence of significance does not necessarily mean the null hypothesis is true; it could also be due to factors like inadequate sample size or other considerations.