Larry Vernon Hedges is a researcher in statistical methods for meta-analysis and evaluation of education policy.
Previously, he was the Stella M. Rowley Distinguished Service Professor of Education, Sociology, Psychology, and Public Policy Studies at the University of Chicago.
He also suggested several estimators for effect sizes and derived their properties.
In 1981, Hedges published a paper describing the unbiased standardized mean difference, the g statistic.
[5] "It turns out that [Cohen's] d has a slight bias, tending to overestimate the absolute value of in small samples.