I have always been surprised how many people let their mistakes just slide, go away, and disappear, only to make them again. If you have allowed your mistakes to not bother you, this post is for you!

Introduction:
There are 2 primary ways we learn and prepare for the GMAT: 1)by studying theory and 2)by taking tests/quizzes. What we learn in those two approaches actually differs. Often when we read a book or watch a lesson, we observe and soak in - we see the big picture. Think of someone explaining you how to drive a stick shift - they tell you how to release the clutch and give gas to the car. Then the quiz part is when you actually sit down to drive the car and realize you don't know how to shift gears, you don't know which gar comes first, how quickly to release the clutch and all other questions you forgot to ask during the "big picture" overview. Thus to soak in the most from each lesson, you need to combine the passive learning with the active testing/quizzing... just one or the other does not work.


How to Analyze Your Mistakes:
Always time yourself. If you are not timing yourself, don't bother reading further.
Save every question you miss/get wrong/guess - my suggestion would be to print every one of them out and build a binder you can grab at any time. You can also look into using an online solution of sorts or an error log and expand it.
For every test/quiz question that you miss or guess, you should ask yourself the following questions:

Why did I make this mistake?
Write a reason for making a mistake - figure out exactly what it is! For example:
Is it not knowing something?
Forgetting a formula?
Confusing concepts?
Not reading the question carefully?
Not following a strategy?
Not recognizing a correct choice A in SC?
Making a silly mistake?
Rushing?

What did it teach me? What did I learn from it?
Each error is a learning opportunity - use it. Don't just say - it was a silly mistake or I made a calculation error but turn it into something more meaningful. Here are a few examples:
You learned that you tend to make calculation mistakes when you do math in your mind or you tend to miss some important words in PS or CR questions
You forgot not know the Triangle area formula
You learned a shortcut for arithmetic
You understand inference and assumptions now and see the difference
You hate RC

What do I need to do so that I never make it again?
The next step is to turn it into an action item. Here are some examples:
How do you ensure that you never make that silly calculation mistake? Well - you always do all math by hand.
Still does not help? You double-check your math when doing word problems or you backsolve to make sure.
Are you skipping important words in CR? You should make a rule to always check for keywords in questions on your CR.
Are you not sure why C or D answer choice in CR? Don't leave the question until you know - most likely that question is discussed in the forum - find it and figure it out. If you can't tell a difference in a CR or RC question answers - that's a sign of a much bigger problem that you need to address ASAP


Other Suggestions For Mistake Review:
Periodically go back to the questions you got wrong, esp the hard mean ones that you did not know how to even approach and make sure you can solve them and know the path to solve them and the key to the solution.
Most likely you know there is a dark little secret about your mistakes, for example, you always miss DS questons or struggle with geometry - that's where you need to camp out and dig until your hand bleed.
Don't get overwhelmed. You may have a lot of ground to cover; try to stick in one area as much as possible before moving on

What do people usually do wrong:
1. Some will do questions only and skip theory/tips/lessons. It is definitely possible to learn how to drive a car without anyone telling you which pedal does what, but it sure is not a very pleasant one. Why not let someone give you a tour and overview first? Not only it is faster, it will also save you from missing a lot of questions since learning solely from questions/quizzes is only good enough when you encounter similar/same questions. When you meet a new question, you will be stuck.
2. Taking too many questions - taking thousands of questions and becoming a machine at pattern recognition (waste of time frankly - i believe that doing 1000 or questions total including quizzes and tests is sufficient). More is not always better. Do you really need to solve 400 of the same arithmetic or geometry questions? probably not, it would probably be much more useful if you were able to solve 40 word problems questions.
3. Not doing the mistake analysis on the questions and that's what the focus of this post is on. Many will classify their mistakes in a pretty error log and stop right there. That's not enough!


What mistakes are you making?
Report what mistakes you make and what worked for you in the past! OR let me know if something is not working and where I can help you - post your specific issues here and I will be happy to provide my recommendations