The ASVAB, or Armed Services Vocational Aptitude Battery, is given to prospective enlistees in any branch of the armed services. The ASVAB tests basic knowledge in several different subject areas. The resulting scores in each area are combined into composite, or line, scores that show for which particular branch or type of service the candidate might be most qualified. The different branches use different combinations of composite scores to make the determination.

Test Sections

The ASVAB tests nine different areas of knowledge. General science covers earth, space, life and physical sciences. Arithmetic reasoning tests basic math knowledge. Word knowledge tests vocabulary and synonyms. Paragraph comprehension tests how well you understand things you read. Mathematics knowledge tests how well you can apply mathematical concepts. Electronics information tests your knowledge of electricity and how electronic devices work. Auto and shop information tests how much you know about auto repair and working with wood or metal. Mechanical comprehension tests your knowledge of structural and mechanical properties. Assembling objects tests how well you understand spatial relationships of objects. These nine tests in different combinations make up the composite scores.

Armed Forces Qualification Test

Armed Forces Qualification Test, or AFQT, determines whether you are qualified to join the military. The different branches have different requirements as to what your score must be to join. The AFQT score is a composite of four sections of the test. The formula is 2VE+AR+MK. Your VE, or verbal expression, score is a combination of your paragraph comprehension and word knowledge scores (VE=PC+WK). That is then doubled and your arithmetic reasoning (AR) and mathematical knowledge (MK) score are added to that.

Army

The Army has nine different composite scores that are used to identify your military occupational specialty, or MOS. The composite scores indicate which job you would be most qualified for. These jobs include clerical, combat, electronics, field artillery, surveillance and communication, general or mechanical maintenance, general or skilled technical or operators and food. For example, high combined arithmetic reasoning, mathematical knowledge and mechanical comprehension (AR+MK+MC), in addition to your qualifying AFQT score, would qualify you for field artillery.

Marine Corp and Air Force

The Marine Corp and Air Force have fewer composite scores than the army, but they use the same basic formulas for determining the scores. The Marine Corp has four composite scores: clerical, electrical, general technical and mechanical. The Air Force also has four composite scores: administrative, electrical, general and mechanical. For example, a high combined score in arithmetic reasoning, mechanical comprehension, electrical information and general science (AR+MC+EI+GS) would qualify you for a Marine Corp electrical position, while an electrical position in the Air Force requires a slightly different combination of scores -- arithmetic reasoning, mathematical knowledge, electrical information and general science (AR+MK+EI+GS).

Navy and Coast Guard

The Navy and Coast Guard use the ASVAB scores a little differently than the other branches. Instead of using the composite scores to help identify a particular specialty, they have a listing of necessary scores associated with each job or rating. For example, to be an air traffic controller in the Navy, you need a minimum score of 220 based on the total of your verbal expression, arithmetic reasoning, mathematical knowledge and mechanical comprehension scores (VE+AR+MK+MC). To be a culinary specialist, you need an verbal expression and arithmetic reasoning (VE+AR) total of 88 or higher.