Quasi-Poisson and negative binomial regression models have equal numbers of parameters, and either could be used for overdispersed count data. While they often give similar results, there can be ...

Zero-inflated Poisson (ZIP) models, which are mixture models, have been popularly used for count data that often contain large numbers of zeros, but their identifiability has not yet been thoroughly ...

The Poisson distribution is a discrete probability distribution. It gives the probability of a certain number of events occurring during a fixed interval. This web calculator allows users to specify ...