The ASVAB is a timed test that measures your skills in a number of different areas. You complete questions that reveal your skills in paragraph comprehension, word knowledge, arithmetic reasoning and mathematics knowledge. These are basic skills that you will need as a member of the U.S. military. The score you receive on the ASVAB is factored into your Armed Forces Qualifying Test (AFQT) score. This score is used to figure out whether you qualify to enlist in the armed services.
There are many misconceptions about what it’s like to serve in the U.S. military. If you don’t know any soldiers personally, you might think of the military as a place for infantry, trudging though rough terrain and loading giant artillery. Although that may have been true in the past, today’s military offers many opportunities that aren’t readily apparent to the typical high school graduate. For example, there are jobs in aviation mechanics, medicine, and accounting. There are also peacekeeping and humanitarian efforts by the United States military that require skills in verbal and written communication. Taking the exam can help you determine if you would be well-suited to one of these occupations.
The AFQT score is a percentile ranking between 1 and 99 that shows where your score is placed in relation to others. For example, if you score a 54 on the AFQT, this means that you scored as well as or better than 54% of other recruits. If you are not satisfied with your score and wish to retake the test to improve your chances at getting selected, you must wait a month before taking it again. You can retake the test as many times as you want, but after 3 attempts the waiting period jumps to 6 months.
The military offers boundless opportunities for people looking for a career in serving their country. The five branches of the military (Army, Navy, Marine Corps, Air Force, and Coast Guard) all have active, reserve, and guard units with jobs unique to each branch and level of commitment. Examples of different jobs include military police, telephone technician, psychological operations specialist, journalist, dental specialist, and oboe player. Each job allows for different levels of advancement depending on factors such as job performance and length of service.

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.
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).
My daughter bought this book to study for her ASVAB test. She took it the first time and did not get the score she needed. So she got this book to help her study and to raise her score. She took her test again and her score raised 14 points. I recommend this book to those that need help studying or need a higher score. The book has a lot of information about the test and has practice questions as well. Overall, the book is very useful for those who want to do well on the ASVAB.
The ASVAB test can be taken at your school or a MEPS (Military Entrance Processing Stations) or MET (Mobile Examination Test) sites.  When the ASVAB is administered at your school, it is usually part of the Student Testing Program or Career Exploration Program.  When the ASVAB is given at MEPS or MET sites, it is part of the Enlistment Testing Program.  The ASVAB test content is the same no matter where you take it, except that you will not have to take the Assembling Objects test if you take the test at your school (as part of the Student Testing Program).  When you take the test in the Student Testing Program you will receive three composite scores (Verbal Skills, Math Skills, and Science and Technical Skills).  When you take the ASVAB as part of the Enlistment Testing Program, you will receive an AFQT (Armed Forces Qualification Test) score and Service composite scores.  These scores are used for assigning your military job.
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.