hD13
If you were to choose between
Veritas and Manhattan Mock Series , giving higher priority to
Verbal Section...
What's your Pick ?
I am in no position to compare but I can tell you a bit about our tests:
The Veritas tests:
-Use Item Response Theory to both deliver questions adaptively and score test sections in the same fashion as the official GMAT.
-Draw from a pool of thousands of questions, all validated using real user data (we're over 100 million user responses now) the way that official GMAT questions are validated. The Veritas Prep Question Bank started as a way to get user data on our questions; now all new questions are validated using unscored, experimental slots in the tests just like GMAC does.
-Use IRT data to identify potentially ambiguous or flawed questions (again, just like GMAC does - the adaptive metrics can signal questions where, for example, high ability users get the question wrong much more frequently than you'd predict based on how medium-ability users do, and that will flag a question to be investigated).
-Generate "error margin" reports for each test and flag scores that fall outside the tolerable range prescribed to us by Dr. Rudner (a pretty rare occurrence nowadays)
And then here's the tricky part I think for any third-party test prep company - our IRT system assigns its intermediate scores (theta values) by comparing performances of Veritas users...but of course our distribution of users isn't the exact same as the official GMAT's pool of users. So to convert from your theta scores to official GMAT scores, we enlisted Dr. Rudner (the retired Chief Psychometrician from GMAC, the guy who was in charge of the official scoring algorithm) to build a data model to convert our theta scores to the scales scores (6-51) and overall scores (200-800) that show up when you finish a Veritas test.
So these tests score as accurately as possible, but as with any IRT test there's an error margin (IRT's scoring system is essentially a probability-based calculation of "what is this user's most likely score?" so there's always a bit of wiggle room...GMAC says that its error margin is +/- 30 points and we're confident that ours is very similar).