New GMATPrep scoring-cant believe this

In 1st Test i also felt that. I got 700 (Q48,V38) IR 5, Q-17 wrong, V - 15 wrong
In 2nd one I got 680 (Q48, V35) IR 8 Q-10 wrong, V-12 wrong

I think it's important to note which questions you answer incorrectly/correctly. If you incorrectly answer all "lower level" questions your score will be lower in comparison to a test where you incorrectly answered all "harder level" questions.

I had written GMAT Prep Test 1 yesterday. I scored 610 (Q50, V23) but in MGMAT exam I scored 670 (Q51, V32). The difference in no. of correct questions in quant was around 1 or 2 but Verbal Scores took me off. In GMAT Prep Verbal I had 24 correct, 17 incorrect whereas in MGMAT I had 22 correct, 19 incorrect.

Please explain to me as to how such a huge difference is there in scoring.

I have two suggestions:

1. GMAT prep test score is the best indicator of your level of preparation. Use all other tests to practice. Use them to learn form your mistakes and identify your weaknesses. Do not make much of the score you achieve in them. The algorithm used by GMAC is not disclosed so prep test companies make their algorithms according to their own judgment. The algorithms are not the same and hence your scores are not comparable.

2. Do not try to analyze your score from only the correct/incorrect number of questions perspective. I understand that we have information about only that perspective and hence we tend to analyze it from every angle but it is a waste of time. As I said before, there are many other factors that decide your score. Since you cannot analyze them, don't waste your time. Instead, use this time to work on an area you don't like. You are sure to gain from it.