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).
The ASVAB is a series of timed aptitude tests that are used to classify selected candidates into appropriate job roles as well as ultimately decide the eligibility of candidates for US military service.  In other words, perform poorly on this test and you could severely limit your opportunities in the military or even prevent yourself from serving.
The vast majority of ASVAB test takers will ultimately not enlist in the military. The ASVAB Career Exploration Program claims that only two-and-a-half percent of those who participate in the ASVAB join the military. Forty-seven percent of those who take the exam indicate an interest in attending a four-year college, and 16 percent of those who take the exam originally indicate some kind of an interest in joining the military.
[1] See two documents: Sims, W.H. and Truss, A.R., A Reexamination of the Normalization of Armed Services Vocational Aptitude Battery (ASVAB) Forms 6, 7, 6E, and 7E (Alexandria, VA: Center for Naval Analyses, September 1980); and Laurence, J.H. and Ramsberger, P.F., Low-Aptitude Men in the Military: Who Profits, Who Pays? (New York: Praeger, 1991).  
25. Use the following passage to answer questions 25 and 26. Sarah is about to fly from New York to Los Angeles. She packs the night before and checks her list three times. Anxiety keeps her from sleeping well. The next morning, she accidentally puts salt in her coffee instead of sugar. She forgets her purse and has to go back to the house to get it. Finally, she arrives at the airport just in time to catch her flight. The flight is uneventful, and soon Sarah is landing at LAX. Her sister is waiting for her. What was the main idea of this passage?
ASVAB stands for Armed Services Vocational Aptitude Battery. It is a test that was originally established in 1968 to measure and predict the success of an applicant in various academic and occupational pursuits in the military. High school and post-secondary students and adults take the test more than one million times each year. If you’re interested in joining the military, or if you already have and would like to take a sample test, simply navigate through the ten practice test sections and take whichever tests you’d like as often as you’d like.
Sergeant Leigh Ann Hester became the first woman to receive the Silver Star, the third-highest U.S. decoration for valor, for direct participation in combat. In Afghanistan, Monica Lin Brown was presented the Silver Star for shielding wounded soldiers with her body.[45] In March 2012, the U.S. military had two women, Ann E. Dunwoody and Janet C. Wolfenbarger, with the rank of four-star general.[46][47] In 2016, Air Force General Lori Robinson became the first female officer to command a major Unified Combatant Command (USNORTHCOM) in the history of the United States Armed Forces.[48]