PSAT:
Preliminary Scholastic Achievement Test. Most students take this test in the fall of their junior year in high school (usually in October). However, many students take it "for practice" at some point during their sophomore year. The PSAT is the same format as the SAT, only it is a shorter exam. Your score on this exam is important because it determines your eligibility for a National Merit Scholarship.
SAT:
Scholastic Achievement Test. Students take this test in the spring of their junior year in high school, in preparation for going to college. Most students take this exam in June, however, many students take the exam again in the fall of their senior year, because they were not satisfied with the score they received in June. There are two subjects tested, verbal skills and math skills. 1.8 million students take the SAT each year.
ACT:
ACT Assessment. Students take this test in place of, or in addition to, the SAT for entrance into college. The exam is offered six times a year, in February, April, June, September, October, and December. It is more widely used in the Midwest region of the US. It covers English, reading, science, and math.
GRE:
Graduate Record Examination. The GRE is required for admission to graduate school. This computerized exam is offered year-round, but only during the first 3 weeks of every calendar month. It tests students on verbal skills, quantitative skills (math), and analytical reasoning skills.
GMAT:
Graduate Management Admission Test. The GMAT is required for admission to business school. This computerized test is offered year-round, but only in the last 3 weeks of every calendar month. It tests students on verbal skills, quantitative skills (math) and analytical writing skills.
LSAT:
Law School Admission Test. The LSAT is required for admission to law school. Most students take this test in October, however, it is also offered in June, December, and February. The LSAT is not a knowledge-based test, but rather a thinking and reasoning-based test. It tests your skills in logic reasoning, logic games, reading comprehension and writing.
MCAT:
Medical College Admissions Test. The MCAT is required for admission to medical school. The MCAT is offered twice a year, in April and August. It has 4 sections: verbal reasoning, biological sciences, physical sciences and a writing sample.
DAT:
Dental Admissions Test. The DAT is required for admission to dental school. It is a computerized test offered year-round. The DAT tests your skills in reading comprehension, natural sciences, quantitative reasoning, and perceptual ability.
Test takers of the GRE, LSAT, MCAT and DAT are usually juniors or seniors in college, though some test takers have been working for several years, and are looking for a career change. Conversely, most GMAT test takers have been out of college for at least 1-2 years since business schools rarely admit students without work experience. More than half of last year's GMAT test takers were over 26.
TOEFL:
Test Of English as a Foreign Language. The TOEFL is required to assess the English proficiency of people who speak English as a non-native language. It is a required exam for those students wishing to begin undergraduate or graduate study in the US. The TOEFL is a computer exam which is given year round. There are 4 sections: listening comprehension, structure, reading comprehension and writing.
USMLE:
United States Medical Licensing Examination. A medical student must pass the USMLE in order to become a licensed physician in the United States. In addition, any doctor licensed outside the country must pass this exam to practice medicine in the US. This test has three levels, called "Steps". The Step 1 exam is given to second year medical students. Most people take the USMLE in May-July or November-December.
NCLEX:
National Council Licensure Examination. A student must pass the NCLEX in order to become a licensed registered nurse in the US. Most nursing students take the exam within 3 months after finishing nursing school. This correlates to a May-July test "season."
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