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).
You often hear people say something like, "I got a 70 on the ASVAB." What they are talking about is the ASVAB AFQT score or Armed Forces Qualification Test Score. Many people think the AFQT score is the overall ASVAB score, but that's not correct. In fact, the AFQT score is derived from only four of the nine ASVAB subtests: Paragraph Comprehension (PC), Word Knowledge (WK), Mathematics Knowlege (MK), and Arithmetic Reasoning (AR).
I thought I was just buying an extra book, that I would most likely not put attention to. But, it was not. This book is filled with practice questions, which I got to study before hand thanks to the "2015 / 2016 ASVAB For Dummies". These two books makes a great combination. One to study and the other to test how far you have improved by testing yourself. I am glad I bought it. I recommend it to everyone who is thinking of taking the ASVAB or the AFQT. Just have in mind, that this book is all about questions, of course it will give you the correct answer in the back of it, but it will not go into detail as much as the "2015 / 2016 ASVAB For Dummies" book.

Using the right ASVAB study guide is an important factor in determining how well you will do on the exam. Each branch of the U.S. Military requires you take an ASVAB (Armed Services Vocational Aptitude Battery) exam.  Your scores on the ASVAB determine not only your entrance into the military, but also your job, advancement opportunities, and potential salary.  The ASVAB exam consists of questions in ten different areas, but in general, the exam is measuring your aptitude in four key areas: Math, Verbal, Science and Technical, and Spatial.  To efficiently prepare for your ASVAB exam, check out our recommended study guides, our free practice exams, our ASVAB flash cards, and our ASVAB study tips.
My name is Chris. I used the AFQT Secrets study guide for five days. I am ex-military retaking the AFQT to reenlist. I just want to say thank you for developing this study guide. My test score in 1988 was 51, today my test score is 89. I would just like to add that I have an A.A.S. Degree, but no math skills above basic high school math. This is where I was lacking, the study guide made it so easy to understand. Like you said this program is worth 100's of dollars. To me 1,000's!! THANKS, Chris G.

First, the ASVAB measures your accumulated knowledge in different areas. So if you are currently in school, stay focused and study hard. Your overall knowledge gained in school will most likely be reflected in your ASVAB score. Second, though accumulated knowledge is important, you may be able to raise your score by preparing specifically for the ASVAB, especially in areas where you are weak. Various study guides are available for this purpose (listed left).
One ASVAB sub-measure, the Armed Forces Qualification Test (AFQT)--which is just a separate analysis of the same tests that focuses only on four of the subtests--is also population-referenced, but its score from 1-99 is a percentile score. This means that if you score a 73, you scored as well as or higher than 73% of test-takers in the national sample.