GMAT Prep Software Analysis and What If Scenarios

I recently took exam 6 from EP2...

In verbal, only missed 4 questions (9,18,37,41) but got only V42...Is it possible that EP2 didn't have enough hard questions to try me for V43/44?

I feel exam 5 (from EP2) exhausted many hard questions...in exam 5 I got V41 even after missing as many as 12 questions (wrongs clustered in the middle and end)...

So probably the first exam from each pack is a better judge and more realistic database of questions...with enough hard arsenal...?

V37: Did not answer last question (SC).

As I can see this post is 4 years old. Are the scenarios still accurate enough?

Hey guys!! First of all, thanks for the amazing work you’ve been doing.

Is it possible to test these scenarios with the new exam pack released by Gmac????
Browsing in this forum (and others) I’ve seen that people have experienced scores not in line with the scenarios in this thread. And most importantly, it looks like they’ve had more problems with the second test they’ve taken; that is, lower scores with more questions answered correctly ( I know the importance of the order in the algorithm). As if the questions pool isn’t big enough to sustain two tests at high scores.

I know for sure that on Quant you do not need to answer 100% of the questions right to get Q51. I have missed problems on the real GMAT and still got a Q51. And on GMATPrep, one can miss 6 questions and still get a Q51. I don't know how it is on the Verbal section of the GMAT, but my guess would be that it would be the same.

I think that the algorithm has multiple time variables, i.e. the time spent per question, in addition to whether you get the question right or wrong, determine the difficulty level of your next question, and next question and so on.

Moreover, the score given per section takes into account not only right and wrong answers per difficulty level, but also the average time spent per question and difficulty level, and how many minutes before the clock runs out you finish the section.

The problem is that the GMATPrep software does not use the exact same algorithm as does the real GMAT.

Hi dabral,

Here is @BB's post stating that this rule is not true anymore. candidate has to submit the choice for final question.
https://gmatclub.com/forum/gmatclub-tests-245692.html#p1896457

I am wondering if this could be confirmed from some official source. Tried to search for it but no NEW official confirmation found.

I gather this is directed at me. I don't know where you've gotten your information about the scoring algorithm, but you are misinformed on some important questions.

It is true, in a literal sense, that some of the algorithm is secret. If someone is administering an IRT-based test, there are certain parameters he or she can freely set without affecting the integrity of the test. Only the designers of the GMAT would know how they've set those parameters. But those are really just technical details. The mathematical basis of the algorithm, which is what is important, is well-known. The GMAT uses a three-parameter IRT model, a fact confirmed in many official research reports. I invite you to research that on your own if you are unsure if what I am saying is true, but someone repeating that is neither lying nor in breach of any confidentiality agreement.

The important information that is not public knowledge, and which you would absolutely need to reverse engineer your score from your responses on a GMATPrep or real GMAT test, are the statistics associated with each test question - the difficulty, discrimination and guessing parameter values. Because those question statistics will vary from test to test, a particular response pattern (right/wrong/right/wrong/etc, for example) will typically produce different scores each time. But those statistics have nothing to do with the underlying algorithm, in the same way that the difficulty levels of questions on a traditional multiple choice test, where your grade is the percentage of questions you answer correctly, have nothing to do with how the test is graded. The GMAT's underlying algorithm is just based on probability theory.

I've read dozens of academic papers in this area, and have programmed an IRT-based algorithm using the same model as the GMAT, so while I'm not a specialist in this area, (anyone doing a graduate degree in the field would know more about it than I do) I do know something about it.

It is true, in a literal sense, that some of the algorithm is secret. If someone is administering an IRT-based test, there are certain parameters he or she can freely set without affecting the integrity of the test. Only the designers of the GMAT would know how they've set those parameters. But those are really just technical details. The mathematical basis of the algorithm, which is what is important, is well-known. The GMAT uses a three-parameter IRT model, a fact confirmed in many official research reports. I invite you to research that on your own if you are unsure if what I am saying is true, but someone repeating that is neither lying nor in breach of any confidentiality agreement.