the corrected sample standard deviation, denoted by :

As explained above, while is an unbiased estimator for the population variance, is still a biased estimator for the population standard deviation, though markedly less biased than the uncorrected sample standard deviation. This estimator is commonly used and generally known simply as the "sample standard deviation". The bias may still be large for small samples ( less than 10). As sample size increases, the amount of bias decreases. We obtain more information and the difference between