H. O. Hartley (1912 – 1980), born Herman Otto Hirschfeld but commonly called HOH, was a German-American statistician. He developed Hartley's test for equality of variances (published in 1950). In 1967 he and J.N.K. Rao published a maximum likelihood method for finding variance components in mixed models. He made significant contributions in mathematical programming, optimization, and survey sampling.
He also founded Texas A&M University's Department of Statistics.
- ^ ASA article by William B. Smith