 Together with the sufficiency principle, Birnbaum's version of the principle implies the famous likelihood principle.Although the relevance of the proof to data analysis remains controversial among statisticians, many Bayesians and likelihoodists consider the likelihood principle foundational for statistical inference.The conditionality principle makes an assertion about an experiment "E" that can be described as a mixture of several component experiments "E"h where "h" is an ancillary statistic (i.e.