The exam is not a “pass or fail” test. Your score in each area reflects your own unique abilities. Of course, you will want to study with the aim of doing your best so that you can qualify for a job that fits your skills and career interests. Your AFQT score is compared to the scores of other recruits in the 18-23 year age bracket to see how your potential measures up.
All test takers are given a summary results sheet that shows their percentile score in every test area. A percentile score of 50 means that a score was achieved that was better than 50 percent of all test takers. Percentile scores are given specifically for test takers of their gender and their grade level. Information obtained from the test is only shared with agencies within the Department of Defense. Test takers are informed that their specific scores will be used for up to two years for recruiting purposes. After two years, test scores will be used for research purposes only.
Achieving the minimum required AFQT score established by an individual branch gets your foot in the door, but the higher you score, the better. For example, if you need a medical or criminal history waiver in order to enlist, the military personnel who make those decisions are more likely to take a chance on you if they think you’re a pretty smart cookie.
The next requirement comes as a fairly basic need for the military to identify possible threats it may be called upon to face. For this purpose, some of the commanding forces and other military, as well as often civilian personnel participate in identification of these threats. This is at once an organisation, a system and a process collectively called military intelligence (MI).
The U.S. Armed Forces are one of the largest militaries in terms of the number of personnel. It draws its personnel from a large pool of paid volunteers. Although conscription has been used in the past in various times of both war and peace, it has not been used since 1972, but the Selective Service System retains the power to conscript males, and requires that all male citizens and residents residing in the U.S. between the ages of 18–25 register with the service.
Again, would you rather go into the ASVAB unsure of what to expect and not knowing if you studied the right things or would you prefer to have taken similar tests covering content commonly tested for on the real thing? Taking practice tests is a great way to build your knowledge, your confidence and your ASVAB familiarity so that you feel relaxed and confident on test day.
If you are interested in using your test scores for military service, you will receive an Armed Forces Qualification Test (AFQT) score. This score is calculated using the scores from the Word Knowledge (WK), Paragraph Comprehension (PC), Arithmetic Reasoning (AR), and Mathematics Knowledge (MK) portions of the exam. AFQT scores are expressed as percentile scores in order to better compare results among all potential military recruits.
AFQT scores are the primary measure of recruit potential. Figure 2.7 indicates the percentage of NPS recruits who scored at or above the 50th percentile (Categories I–IIIA) since FY 1973. Numerical data are in Appendix D, Table D-12. The drop in Category I–IIIA recruits after FY 1976 was due primarily to the miscalibration of the ASVAB.  In FY 1976, when new versions of the ASVAB were introduced, an error in calibrating the score scales made the new versions "easier" than the old versions (i.e., applicants received test scores higher than their actual ability). In FY 1980, an independent study of the calibration was made and the test was correctly calibrated. Then, Congress added legal provisions stipulating that no more than 20 percent of accessions could be in Category IV and that such accessions had to be high school diploma graduates.  However, as previously stated, Defense Planning Guidance decreases this limit even further, allowing no more than 4 percent of recruits to come from Category IV.