Well since everybody is misguided and ignorant, maybe you could explain it instead of insulting people.
Haha, okay let me explain it the best I can. The last time I explained it, most people completely ignored what I said, and went on to complain about how, judging on how their percentiles look, they got the shaft.
This is all from the DAT User Manual, so follow along as well as we can kids. Mr. Bear will explain once and for all, in layman terms, on how the DAT is scored.
1. Not all question you answered on the DAT will be marked. There are experimental questions that will be asked, and are eligible to enter into pool of marked questions on future tests. For example, only 75 out of the 90 questions on the PAT is marked. The 15 will be assessed on the difficulty, judging by how many people get it right or wrong. A difficulty parameter is assigned to every question, and questions that have difficulty parameters of 0.4 to 0.7 will be used as future test questions, with questions closer to the 0.7 being preferred.
2. So from these questions, a test is constructed, and scored. The sum of the difficulty parameters is used to gauged the difficulty of the test. There are multiple versions of the test, and if you have a certain version, then ALL of the questions, from the natural sciences to QR, will be the same.
3. You get a raw score from your performance on the DAT. The percentiles are relative to test takers who took the exact same test as you and received the same raw score.
4. Your individual score for each section is then standardized. Let's use Biology as an example. If person A got 37/40 on Biology, they would get a higher percentile than someone who took test B and got 35/40. But what if the sum of the difficulty parameter on test B is higher, should person B be punished for getting a harder test? of course not. When they do the standardization, the numbers will be closer together.
That's why percentiles are there, just to give a measuring stick on how you performed on that particular test. Standardizing will adjust for test difficulty, giving adcoms numbers so they can compare applicants who took different versions of the test.