# Techniques (Advanced)

In order to determine whether the difference between variants is statistically significant, we use various statistical hypothesis testing techniques:

If the goal metric is well understood – including the range of its nominal values, the frequency and scale of outliers etc, we use Bayesian Inference which enables us to perform hypothesis testing even for small sample sizes.

When the number of measurements is high, we also use bootstrapping techniques after data normalization and outlier detection.

When the sample size is high enough, bootstrapping and Bayesian inference lead to the same results, but bootstrapping is less resource intensive.