In statistics,<unk> , named after Friedrich<unk> , is the use of n − 1 instead of n when estimating variance, where n is the number of observations in a sample. n − 1 is used to correct for the fact that samples understate the variance in the population on average.  See bias of an estimator.
Bessel's correction
Tetralogy of fallot surgical techniques
Cor triatriatum surgery
Papillary muscle rupture surgery
Atrioventricular block surgery
Ventricular tachycardia surgery
Dextrocardia surgery
Long QT Syndrome surgery