The underlying model used for the ASVAB is a three-parameter logistic (3PL) model. This model represents the probability that an examinee at a given level of ability will respond correctly to an individual item with given characteristics. The characteristics used are difficulty, discrimination and guessing (this refers to the likelihood that a very low ability examinee would respond correctly simply by guessing).
PiCAT testing does require a shorter “verification test” for new recruits. This is in the form of a short, proctored test that lasts about a half an hour. Depending on circumstances, recruits may be required to take this verification test at a Military Entrance Processing Station, or within 30 days of taking PiCAT if the recruit is not going to MEPS right away. Those who do not pass the verification test will be required to take the ASVAB.
The ASVAB is routinely reviewed to eliminate any potential biases from questions and scoring. The exam underwent a major revision in 2002. Two years later, a renormalization of the percentile scoring system was performed to ensure that a 50 percent score represented performing better than 50 percent of all test takers. The 10-section ASVAB improves the matching of volunteers with available jobs and helps match job openings with qualified individuals.
The Armed Forces Qualification Test (AFQT) is used by all of the Services to determine if an applicant is eligible for the military. Four of the ASVAB subtests are combined to form the AFQT. It measures general cognitive ability and is composed of verbal and mathematics subtests. AFQT scores are grouped into categories for reporting purposes. The table below shows the AFQT categories and the percentile score ranges corresponding to the categories. Applicants that score in AFQT category IIIA or higher may qualify for enlistment incentives.