level of significance
Quick Summary
In statistics, statistical significance determines if an observed result is due to inherent qualities or random variance within a sample. A result is considered statistically significant if the probability of it occurring by chance is extremely low, given a null hypothesis (a claim of no difference or relationship) is true.1
This is assessed through hypothesis testing, where a p-value is calculated. The p-value represents the probability of the observation occurring if the null hypothesis is true. This p-value is compared to a predetermined significance level (often denoted as alpha, (\alpha)), typically set at 0.05. If the p-value is lower than the significance level, the null hypothesis is rejected, and the result is deemed statistically significant, indicating it's unlikely due to chance.123
It's important to note that statistical significance does not imply the size, importance, or practical application of an outcome; it solely indicates that the difference observed is not random.1
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