Bias occurs when an item or test unfairly favors one group over the other. The ASVAB Testing Program routinely conducts analyses to make sure that items and scores are fair and unbiased. Analyses of ASVAB scores suggest that there is some adverse impact on the ASVAB. Namely, qualification rates for African-American/Black and Hispanic applicants are less than four-fifths of the qualification rates for Caucasian/White and Non-Hispanic White applicants. These minority groups have lower qualification rates both for entry into the military and enlistment incentives.
The occurrence of adverse impact does not necessarily mean the ASVAB is biased, however. If a test is equally valid for minority and majority groups, then it is not considered to be biased. A test is equally valid if minority and majority group members with the same test scores have the same performance on an outcome, such as final school grades. Previous research on the ASVAB technical tests has suggested that the tests are equally valid for both males and females, and African-Americans/Blacks and Caucasians/Whites. Also, the degree of adverse impact observed on the AFQT tests is similar to the adverse impact observed on other high-stakes test batteries with similar tests. This all suggests that the adverse impact observed in the ASVAB reflects a societal phenomenon, rather than a bias in the test.