Could you please explain me what’s this CAT all about & why it’s so difficult to estimate the score?
The GMAT (CAT) adapts itself according to your performance to the test. Thus there’s no standard measure for GMAT as being difficult or easy. For some students it may throw easy questions & for some it may throw very difficult questions. When you answer a question correctly then next question will be harder. If you answer the question incorrectly the next question will be easier. Thus the exam tries to gauge your ability level by checking your performance (ie how well you perform at various levels of difficulty). Thus to conclude, it is observed that your score shoots higher if you answer more ‘harder questions’. (i.e. the more you roam at the high level during GMAT CAT higher score you’ll get ) Some people argue that to gauge the test taker’s ability level, the initial questions are sensitive and most critical; they have valid points, however these experimental questions (un-scored items placed randomly throughout the test) makes GMAT scoring algorithm so complex and difficult to comprehend that it becomes almost impossible to estimate the real GMAT score.
One more additional point in CAT, (from the official source) is last questions plays very significant role in GMAT score & if left blank due to lack of time hampers the score severely.