H. O. Hartley born Herman Otto Hirschfeld but commonly called HOH, was a German

Germans

The Germans are a Germanic ethnic group native to Central Europe. The English term Germans has referred to the German-speaking population of the Holy Roman Empire since the Late Middle Ages....

-American

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 statistician

Statistician

A statistician is someone who works with theoretical or applied statistics. The profession exists in both the private and public sectors. The core of that work is to measure, interpret, and describe the world and human activity patterns within it...

. He developed Hartley's test

Hartley's test

In statistics, Hartley's test, also known as the Fmax test or Hartley's Fmax, is used in the analysis of variance to verify that different groups have a similar variance, an assumption needed for other statistical tests.It was developed by H. O...

 for equality of variances (published in 1950). In 1967 he and J.N.K. Rao published a maximum likelihood

Maximum likelihood

In statistics, maximum-likelihood estimation is a method of estimating the parameters of a statistical model. When applied to a data set and given a statistical model, maximum-likelihood estimation provides estimates for the model's parameters....

 method for finding variance components in mixed model

Mixed model

A mixed model is a statistical model containing both fixed effects and random effects, that is mixed effects. These models are useful in a wide variety of disciplines in the physical, biological and social sciences....

s. He made significant contributions in mathematical programming, optimization, and survey sampling.

He also founded Texas A&M University

Texas A&M University

Texas A&M University is a coeducational public research university located in College Station, Texas . It is the flagship institution of the Texas A&M University System. The sixth-largest university in the United States, A&M's enrollment for Fall 2011 was over 50,000 for the first time in school...

's Department of Statistics.