Behrens–Fisher problem
Mathematical problem / From Wikipedia, the free encyclopedia
In statistics, the Behrens–Fisher problem, named after Walter-Ulrich Behrens and Ronald Fisher, is the problem of interval estimation and hypothesis testing concerning the difference between the means of two normally distributed populations when the variances of the two populations are not assumed to be equal, based on two independent samples.
Unsolved problem in statistics:
Is an approximation analogous to Fisher's argument necessary to solve the Behrens–Fisher problem?