The test measures competency in 9 different subjects, which include General Science, Electronics Information, Auto and Shop Information, Mechanical Comprehension, Assembling Objects, Word Knowledge, Paragraph Comprehension, Arithmetic Reasoning, and Mathematics Knowledge. These last four sections- Word Knowledge, Paragraph Comprehension, Arithmetic Reasoning, and Mathematics Knowledge are the most important, as they make up something called the AFQT (Armed Forces Qualifications Test). An applicant’s AFQT score is what determines whether or not they are able to serve in the military at all, as each branch has minimum scores for enlistment.

For almost a century, the U.S. military has been a pioneer in the field of using aptitude tests to evaluate an individual’s potential for service. The organization also uses the test to determine aptitude for various military occupational specialties (MOS). The use of aptitude tests began during World War I. While the group-administered Army Alpha test measured verbal and numerical ability as well as general knowledge, the Army Beta test was used to evaluate illiterate, unschooled and non-English speaking volunteers and draftees. The Army and Navy General Classifications Tests replaced the Alpha and Beta tests as a means to measure cognitive ability during World War II. The results of these tests, as well as additional classification exams, were used to assign recruits to a particular MOS.

In addition to the AFQT, the military also includes additional composite scores, often called 'line scores.' These scores are based on variations of the ASVAB's ten subtests and are required for certain military careers. For example, an Army Clerical (CL) score is determined by looking at an individual's Word Knowledge (WK), Paragraph Comprehension (PC), Arithmetic Reasoning (AR) and Mathematics Knowledge (MK) scores. Note that the subtests considered for different careers can vary depending on the military branch.
Don’t let the PC section of the test throw you for a loop. Unlike the individual multiple choice questions in other sections, here you will need to read a paragraph and answer several questions in a row based on that one paragraph. The people who designed this section of the exam really knew how to make sure you are able to read detailed (and often boring) documents, remember the details of what you read, understand why they’re important, and be able to pick out the key concepts they illustrate. When you read each paragraph, it’s helpful to know the kinds of questions you’ll be asked at the end. There are basically four kinds of questions to test your comprehension:
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.