GMAT Strategy

Hi,

I have two questions.

First, I have about a month left before taking the actual test and I have done Kaplan, Kap 800, Princeton, Manhattan, and OG 11. I have taken five princeton review diagnostic tests and they range from 650 to 730. I hear so much about Kap test that I'm kind of afraid to take it. My first question is what else can I do between now and before the test? I have OG 10, but should I do that or do SC 1000 and CR 1000 instead? Besides Kap and GMATprep, are there any other practice tests I can do? Plus, I'm thinking about looking at all the posts in this website to get some questions as well. Do you think that's a good idea?

Second, my test score is kind of erratic. I got 730 on my second of five practice tests and the score actually consistently went down to 680, 690, and 630! My friend is suggesting that I take a prep course, but do you guys have any other suggestion? One big thing I noticed from my last 3 tests is that I got #2 of math on the 3rd test wrong and #2 and #3 of verbal wrong on the 4th and 5th tests repectively. Besides that any other suggestion on what I may be doing wrong?

Sorry for a long message and thank you in advance. I guess there are more than 2 questions in this post... sorry about that..

Material: I would stick with OG10 over the 1000 materials. If you've done OG11 there will be overlap so the better choice would be OG review and math books. They contain no overlap with OG11.

CATS: MGMAT has a pretty good CAT algorithm-wise. The questions themselves are very hard in terms of Q and a bit off in terms of V IMO. Aside from GMATPrep and PowerPrep, I consider MGMAT to be the next best CAT

CAT Score: Was this pattern of missing questions in the first ten found in the PR CAT? I found the same problem in my PR CATS. I believe that the PR CAT is severely flawed algorithmically because it appears they followed their own advice too closely and severely penalize you if you miss a question within the first 10. On my CATS, I consistently missed 1 question on the first 10 and was never able to break 600. Take PowerPrep and GMATPrep and use those as the most accurate indicator of your score. Check other posts for opinions on other CATS.

thank you for your reply..

one more question though.
i've done OG review and math book in addition to OG 11th edition. Does this mean that I've basically done most of the OG 10th edition? If that's the case should I just go ahead and finish 1000Qs?

Again, I really appreciate your time.