dave785 wrote:
I'm somewhat familiar with how adaptive tests work and I was wondering if the sentence correction ranking system is integrated in the same question-placement set as the critical reasoning and reading comprehension.
The reason I ask is that I tend to do very very well on critical reasoning and reading comprehension, so in my practice tests (and the first GMAT I took) I tended to get extremely hard sentence correction questions too, which I would subsequently bomb. It felt like I didn't know hardly any of the SC answers past the first two.
If I'm making a lot of harder than normal questions (CR + RC) but missing a lot of them too (SC) how would this affect my score? Wouldn't it cause the standard deviation to increase drastically, making it difficult for the program to accurately rank me?
Good news is that SC is the easiest to fix of the three, so hopefully when I take it again it won't be a problem. I'm just curious how the ranking algorithm deals with diverse data points compared to grouped data points.
Hi Dave785, the GMAC doesn't release all the details of its scoring algorithm, but the general idea is that the algorithm adjusts your score based on the difficulty of questions you correctly answer. The topic of the question (be it strengthening, weakening or even RC vs CR) is not accounted for in the scoring algorithm. The types of questions are only relevant to the types of questions you should study. The breakdown is roughly 1/3 RC, 1/3 SC and 1/3 CR, but your actual exam may vary a little from this, so you might face more SC questions on one exam than on another.
Since all questions are scored equally, it won't matter what questions you got wrong. Practice tests will break down your results to help you study. The actual exam will just look at the difficulty level of the questions you got right and the difficulty level of the questions you got wrong, and then assign you a score. The only thing I'll mention is that the scoring algorithm penalizes and rewards long strings of incorrect or correct answers (respectively). However this doesn't even matter in your situation because I've seen 5-6 questions in a row on the same topic, so it's not like it's going to oscillate between the three in any meaningful pattern.
I guess bottom line is don't worry about it, but try strengthening your SC if you know it's your Achilles heel.
Best of luck!
-Ron