Because minority group students typically perform less well on the test as a whole, the effort to increase reliability also increases bias against minorities. According to other research, items which facilitate ranking and sorting are often items which, perhaps unintentionally, factor non-school learning and social background into the questions. This common test development procedure exacerbates the existing inequities of schooling. When used in high-stakes testing, biserial correlation helps ensure that at least some students who know the material and ought to pass the tests do not. Those students are overwhelmingly low-income, of color, with English as a second language, or have special needs.
Alternatives do exist.
One is to use different item selection procedures. Given more than two racial groups to balance, however, this might not be a simple process. This approach has two major problems. First, it assumes that performance on the many sub-topics in a subject, such as algebra and geometry in math, is due to one, not multiple and possibly different, abilities. Second, standards in various subjects assume students will learn cognitively complex skills.