Hi Dabral,
Thanks for the observations...I felt the same way, and it also showed in my respective scores on each test. Do you think this might be because both tests in this Exam Pack (5 and 6) are pulling from the same composite question pool?
For GMAT 700+ scorers, it is easy to understand how a higher-than-usual amount of questions in the pool (in this case, double) would result in a student getting twice as many hard questions as usual.
From what I understand, each test of 90 questions comes from a pool of about 150 possible questions (if anyone has a hard number on this, I'd appreciate it). It is possible that both tests 5 and 6 are pulling from the same pool of about 300 questions...meaning that on our first test (test 5), there were almost twice as many hard questions available as usual, which could account for our noticing a higher level of difficulty on that test. And on the second test, there were fewer harder problems left to give, because the GMAC doesn't want us to see the same question on each test.
This could also have consequences for students on the lower rung of the scoring ladder, who might see an easier test than usual on test #5 because of this (potential) software flaw.
The GMAC has repeatedly stressed in its official materials that a correct answer to a hard question will not always be followed by another hard question, because there is a limited number of hard questions of that type in the pool. However, the question that I have yet to answer is, is the pool of questions on the actual GMAT 300 questions, or is it closer to half of that? I have yet to discover the answer, because the GMAC has always released its practice CATs in sets of two.
If it is the latter, then in order to make these exams more realistic--and equally difficult--the GMAC would do well to release a GMATPrep software update that limits each test to half of the 300 or so possible questions (quant and verbal combined).
I am a fan of your work, and I keep sending students your way for helpful videos, information etc.
-Brian