Additive smoothing

In statistics, additive smoothing, also called Laplace smoothing (not to be confused with Laplacian smoothing as used in image processing), or Lidstone smoothing, is a technique used to smooth categorical data. Given an observation from a multinomial distribution with trials, a "smoothed" version of the data gives the estimator:

Additive smoothing

In statistics, additive smoothing, also called Laplace smoothing (not to be confused with Laplacian smoothing as used in image processing), or Lidstone smoothing, is a technique used to smooth categorical data. Given an observation from a multinomial distribution with trials, a "smoothed" version of the data gives the estimator: