Significance level (alpha)

The significance level, often represented by the Greek letter alpha (α), is a threshold in statistical tests that helps researchers determine whether their findings are meaningful. Specifically, it defines the probability of rejecting the null hypothesis (the idea that there is no effect) when it is actually true. Commonly set at 0.05, this means there's a 5% chance of concluding there's an effect when there is none. A lower alpha value indicates stricter criteria for claiming results are statistically significant, reducing the likelihood of false positives, or errors where researchers find effects that don’t actually exist.