Monday, May 31, 2010

Medical College Admission Test(MCAT)

The Medical College Admission Test, commonly known as the MCAT, is a computer-based standardized examination for prospective medical students in the United States and Canada. It is designed to assess problem solving, critical thinking, written analysis, and writing skills in addition to knowledge of scientific concepts and principles. Prior to August 19, 2006, the exam was a paper-and-pencil test; since January 27, 2007, however, all administrations of the exam have been computer-based.

Evolution of the MCAT

The Moss Test: 1928–46

In the 1920s, dropout rates in US medical schools soared from 5% to 50%, leading to the development of a test that would measure readiness for medical school. Physician F.A. Moss and his colleagues developed the "Scholastic Aptitude Test for Medical Students" consisting of true-false and multiple choice questions divided into 6-8 subtests. Topics tested included visual memory, memory for content, scientific vocabulary, scientific definitions, understanding of printed material, premedical information, and logical reasoning. The score scale varied from different test forms. Though it had been criticized at the time for testing only memorization ability and thus only readiness for the first two years of medical school, later scholars denied this. In addition to stricter medical school admission procedures and higher educational standards, the national dropout rate among freshman medical students decreased from 20% in 1925 to 1930 to 7% in 1946

A simpler test: 1946–62

Advancements in test measurement technology, including machine scoring of tests, and changed views regarding test scores and medical school readiness reflected the evolution of the test in this period. The test underwent three major changes. It now had only four subtests, including verbal ability, quantitative ability, science achievement, and understanding modern society. Questions were all in multiple-choice format. Each subtest was given a single score, and the total score was derived from the sum of the scores from the subtests. The total score ranged from 200–800. The individual scores helped medical school admission committees to differentiate the individual abilities among their candidates. Admission committees, however, did not consider the "understanding modern society" section to be of great importance, even though it was created to reward those with broad liberal arts skills, which included knowledge of history, government, economics, and sociology. Committees placed greater emphasis on scores on the scientific achievement section as it was a better prediction of performance in medical school.

From 1946–48, the test was called the "Professional School Aptitude Test" before finally changing its name to the "Medical College Admission Test" when the developer of the test, the Graduate Record Office (under contract with the AAMC) merged with the newly-formed Educational Testing Service (ETS). In 1960, the AAMC transferred its contract over to The Psychological Corporation, which was then in charge of maintaining and developing the test.

Status quo: 1962–77

From 1962–77, the MCAT retained much of its previous format, though the "understanding modern society" section was renamed as "general information" due to its expanded content. Handbooks at the time criticized the test as only a measure of intellectual achievement and not of personal characteristics expected of physicians. Responding to this criticism, admission committees took different approaches in measuring personal characteristics among their applicants.

Phase Four: 1977–91

During phase four, the MCAT underwent several changes. The "general information" section was eliminated and a broader range of knowledge was tested. At this point, topics tested included scientific knowledge, science problems, reading skills analysis, and quantitative skills analysis. Individual scores were reported for biology, chemistry, and physics rather than a composite science score, thus six different scores for the whole test were reported. The score scale changed to 1–15 as opposed to 200–800 from previous versions of the test. Cultural and social bias was minimized. Though the AAMC claimed the new version intended to evaluate "information gathering and analysis, discerning and formulating relationships, and other problem-solving skills," no research supported this claim.

New changes: 1992–present

The test changed again. Though the test was still divided into four subtests, they were renamed to the verbal reasoning, biological sciences, physical sciences, and writing sample sections. Questions retained the multiple-choice format, though the majority of the questions are divided into passage sets. Passage-based questions were implemented to evaluate "text comprehension, data analysis, ability to evaluate an argument, or apply knowledge from the passage to other contexts." A new scoring scale was also implemented. The total composite score, which ranges from 3–45, is based on the individual scores of the verbal reasoning, biological sciences, and physical sciences, which each have a score range of 1–15. The writing sample, which consists of two essays to be written within 30 minutes for each, is graded on a letter scale from J-T. This question structure and scoring scale still exist today.

On July 18, 2005, the AAMC announced that it would offer the paper-and-pencil version of the MCAT only through August 2006. A subset of testing sites offered a computer-based version of the full-length exam throughout 2005 and 2006. The present, shorter, computer-based version of the test debuted in January 2007. The exam is now offered numerous times annually, and scored more quickly.

The MCAT today

The exam is offered 25 or more times per year at Prometric centers.[4] The number of administrations may vary each year. Most people who take the MCAT are undergraduates in college in their Junior or Senior year of college before they apply to medical school. Ever since the exam's duration was shortened to 4.5–5 hours, the test may be offered either in the morning or in the afternoon. Some test dates have both morning and afternoon administrations.

The test consists of four sections, listed in the order in which they are administered on the day of the exam:

* Physical Sciences (PS)
* Verbal Reasoning (VR)
* Writing Sample (WS)
* Biological Sciences (BS)

The Verbal Reasoning, Physical Sciences, and Biological Sciences sections are in multiple-choice format. The Writing sample consists of two short essays that are typed into the computer. The passages and questions are predetermined, and thus do not change in difficulty depending on the performance of the test taker (unlike, for example, the Graduate Record Examination).

The Physical Sciences section assesses problem-solving ability in general chemistry and physics and the Biological Sciences section evaluates these abilities in the areas of biology and organic chemistry. The Verbal Reasoning section evaluates the ability to understand, evaluate, and apply information and arguments presented in prose style. The Biological Sciences section most directly correlates to success on the USMLE Step 1 exam, with a correlation coefficient of .553 vs .491 for Physical Sciences and .397 for Verbal Reasoning. Predictably, MCAT composite scores also correlate with USMLE Step 1 success.

The Physical Sciences section is administered first (prior to the April 2003 MCAT, Verbal Reasoning was the first section of the exam). It is composed of 52 multiple-choice questions related to general chemistry and physics. Exam takers are allotted 70 minutes to complete this section of the exam.

The Verbal Reasoning section follows the Physical Sciences section and an optional 10 minute break. Exam takers have 60 minutes to answer 40 multiple-choice questions evaluating their comprehension, evaluation, and application of information gathered from written passages. Unlike the Physical and Biological Sciences sections, the Verbal Reasoning section is not supposed to require specific content knowledge in order to perform well.

Prior to the computerization of the MCAT there was a 60 minute lunch break after the Verbal Reasoning section followed by the Writing Sample. With the new Computer-Based Testing format the 60 minute lunch break has been substituted by an optional 10 minute break. The Writing Sample gives examinees 60 minutes to compose responses to two prompts (30 minutes for each prompt, separately timed), the prompts are predetermined and there are only two prompts to choose from. Each essay is graded on a scale of 1 to 6 points twice. The scores from individual essays are added together and then converted to a letter scale of J, the lowest, through T, the highest.

After the Writing Samples, there is an optional 10 minute break followed by the Biological Sciences section. Examinees have 70 minutes to answer 52 multiple-choice questions related to organic chemistry and biology.


Scores for the three multiple-choice sections range from 1 to 15. Scores for the writing section range alphabetically from J (lowest) to T (highest). The writing section is graded by a human reader and a computerized scoring system. Each essay is scored twice - once by the human reader and once by the computer - and the total writing sample score is the sum of the four individual scores. The total raw score is then converted to an alphabetic scale ranging from J (the lowest) to T (the highest).

The numerical scores from each multiple-choice section are added together to give a composite score. The score from the writing sample may also be appended to the composite score (e.g. 35S). The maximum composite score is 45T. According to the AAMC, the average 2008 MCAT score for U.S. medical school applicants was 28.1P, while for matriculants it was 30.9P. There is no penalty for incorrect multiple choice answers, thus even random guessing is preferable to leaving an answer choice blank (unlike many other standardized tests). Students preparing for the exam are encouraged to try to balance their subscores; physical, verbal, and biological scores of 12, 13, and 11 respectively may be looked upon more favorably than 14, 13, and 9, even though both amount to the same composite score.

The standard deviation is 2.0-2.3 depending on the year and form of the exam.


Like some other professional exams (e.g. the Graduate Management Admission Test (GMAT)), the MCAT may be voided on the day of the exam if the exam taker is not satisfied with his or her performance. It can be voided at any time during the exam, or during a five-minute window that begins immediately after the end of the last section. The decision to void can only be based on the test taker's self-assesment, as no scoring information is available yet—it takes 30–35 days to get scores back.

The AAMC prohibits the use of calculators, timers, or other electronic devices during the exam. Cellular phones are also strictly prohibited from testing rooms and individuals found to possess them are noted by name in a security report submitted to the AAMC. The only item you may bring into the testing room with you is your photo ID. If you wear a jacket or sweater, it may not be removed in the testing room.

It is no longer a rule that students must receive permission from the AAMC if they wish to take the MCAT more than three times total. The limit with the computerized MCAT is three times per year, with no lifetime limit. An examinee can register for only one test date at a time, and must wait two days after testing before registering for a new test date.

Scaled MCAT exam results are made available to examinees approximately thirty days after the test via the AAMC's MCAT Testing History (THx) Web application. Examinees do not receive a copy of their scores in the mail. Examinees are also not given a copy of their raw score. MCAT THx is also used to transmit scores to medical schools, application services and other organizations (at no cost).


Like most standardized tests, there are a variety of preparatory materials and courses available. The AAMC itself also offers a select few tests for purchase at their website and one free sample test on their main website at

Some students taking the MCAT use a test prep company. Students who do not use these courses often rely on material from university text books, MCAT preparation books, sample tests, and free web resources.