Generalizability in Factorable Domains: "Domain Validity and Generalizability"1

Abstract

It is shown that if a behavior domain can be described by the common factor model with a finite number of factors, the squared correlation between the sum of a selection of items and the domain total score is actually greater than coefficient alpha. Equality is attained only if the selected items are parallel. Generalizability can be correctly assessed as a function of the item uniquenesses and the test variance.