Definition of Poisson distribution in English:

Poisson distribution

Pronunciation /pwäˈsän ˌdistrəˌbyo͞oSH(ə)n/ /pwɑˈsɑn ˌdɪstrəˌbjuʃ(ə)n/


  • A discrete frequency distribution which gives the probability of a number of independent events occurring in a fixed time.

    ‘In this he was the first to note that events with low frequency in a large population followed a Poisson distribution even when the probabilities of the events varied.’
    • ‘Because of the extreme non-normality of these scores, we used a statistical test for two Poisson distributions.’
    • ‘The Poisson distribution provides a statistical description of the number of enzymes in the droplet.’
    • ‘By using recurrence relations for the probability distributions, they show that in several cases the numbers of homozygous and heterozygous loci have independent Poisson distributions.’
    • ‘Note that the numbers of mutations and gene conversion events per generation follow Poisson distributions.’


Late 19th century named after the French mathematical physicist Siméon-Denis Poisson(1781–1840).