Editing Statistical classification (section)

==Bayesian procedures==

Unlike frequentist procedures, Bayesian classification procedures provide a natural way of taking into account any available information about the relative sizes of the different groups within the overall population.<ref>{{Cite journal |doi = 10.1093/biomet/65.1.31|title = Bayesian cluster analysis|year = 1978|last1 = Binder|first1 = D. A.|journal = [[Biometrika]]|volume = 65|pages = 31–38}}</ref> Bayesian procedures tend to be computationally expensive and, in the days before [[Markov chain Monte Carlo]] computations were developed, approximations for Bayesian clustering rules were devised.<ref>{{Cite journal | doi=10.1093/biomet/68.1.275| title=Approximations to Bayesian clustering rules| year=1981| last1=Binder| first1=David A.| journal=[[Biometrika]]| volume=68| pages=275–285}}</ref>

Some Bayesian procedures involve the calculation of  [[group-membership probabilities]]: these provide a more informative outcome than a simple attribution of a single group-label to each new observation.