Posts tagged: count data

The Poisson Distribution

January 16, 2018

The Poisson distribution is the workhorse for count data — the number of times something happens in a fixed interval of time, space, or volume. Named after French mathematician Siméon Denis Poisson (1781-1840), it appears everywhere: call-centre arrivals, radioactive decay counts, hospital admiss...

Fisher’s Exact Test

August 30, 2016

Fisher’s exact test is used to compare counts and proportions between groups when small samples of nominal variable are available. It assumes that the individual observations are independent, and that the row and column totals are fixed, or “conditioned.”