The story
Named after Friedrich Bessel.
Etymology from Wiktionary, CC BY-SA 4.0.
Bessel's correction
Today it means: The use of n − 1 instead of n in the formula for the sample variance and sample standard deviation, where n is the number of observations in a sample. This corrects the bias in the estimation of the population variance and partially corrects the bias in the estimation of the population standard deviation, but often also increases the mean squared error in these estimations. Full definition →