The last major review of grade adjustment methods developed to improve
the prediction of academic performance is Linn's 1966 article. Since
then, several other statistical methods have been developed and used t
o make grades from different courses more directly comparable. In seve
ral instances, these methods have improved the understanding of the ob
served phenomena of differential predictive validity for women and for
minority students. Each method is based on a different statistical me
thodology and set of assumptions about the data and tested on a differ
ent data set. This article reviews the studies in this area over the a
st 27 years and discusses this research in the context of selection in
admissions and of the prediction of student performance in college.