Overcome your phobia, ace the DI section in CAT!

Vibhor Dhote is a Chemical engineer from Institute of Chemical Technology (UDCT), Mumbai. He worked for a couple of years as a Business Analyst with Evalueserve, Gurgaon. He later worked with his family business for a year as a business development officer. He scored 98.47 in CAT 2014 and is raring to join one of the premier Bschools this June. Vibhor is a blogger, photography enthusiast and a cricket freak.
Having screwed up CAT 2013 due to LR (Logical Reasoning) & DI (Data Interpretation), and then coming back to score well in CAT 2014 (with Logical Reasoning being my game changer, as I solved all the 4 LR sets in a slot where most of the others could hardly solve 2), I would like to add my 2 cents on how to improve your LRDI section. As many others would already have told you, Data Interpretation needs a lot of practice, but what a lot of people forget to tell you is what is it that you should practise. It is very important to be able to wisely choose which DI set to attempt, as starting with a set randomly and ending up wasting time on it can lead to panic and you may end up screwing the rest of your exam. I was in a similar situation as I used to take too much time for solving DI sets and a lot of questions inaccurately. These are a few pointers on how to choose which DI problem to attempt:
1. Comfort level with the type:
Sometimes you will see a new type of graph or a new type of data set given in the question. Have a quick look at it and then read the question for about a minute quickly. If you don't seem to get the hang of it at all, just forget about it for now. If you think, you can crack it but will take some time, keep it for later. In the first round, always try and solve problems you know you will be able to solve and quickly. The best source of question sets for LR and DI for CAT are the previous years' CAT papers. I know it's a cliche and a lot of others also would have told you this already, believe me it is the single most important thing that any serious CAT aspirant MUST do religiously! CAT papers would not only familiarize you with the kind of questions and the difficulty level you can expect in the actual paper, it is also an excellent question bank with large number of good questions.
( Related : Please check LR sets and DI sets from previous CAT papers )
Having solved decent number of question sets from previous CAT papers as well as the mock tests that you give, you would realize where you lack.
I have generally seen:
 Data Interpretation can be solved, but it sometimes takes too much time
 Logical Reasoning can sometimes take too much time, or you just don't get the logic at all
I suggest you make categories of problem types in each of these sections and then identify which ones you are comfortable with and which ones you not so much. This way you will know which are the ones you need to work more on.
Examples of categories can be:
 LR: Cubes, Rankings, Arrangements (Linear/Circular), Table based LR sets, Games, SET theory based etc.
 DI:Line and bar charts, Pie charts, Tables based et
2. Numbers associated with the graphs:
Data Interpretation: To improve your speed, you have to be firstly quick at calculations. Try and do calculations mentally as much as possible.
Learn:
 Squares at least till 30
 Cubes at least till 20
 Sq. roots till 10
 Fractions to percentage conversions
These will help you greatly speed up your calculations and save you a lot of time.
Numbers in the DI set will tell you roughly which one is going to take more time to solve.
Example:
86, 114, 320 is better than 54,895
15%, 24% is better than 17.5%, 22.8% etc
Also check the numbers in the options.Try options or do approximate calculations where it works. Remember, you just have to tick the right answer. CAT is not a subjective exam.
Logical Reasoning: Here the trick is to familiarize yourself to as many different types as possible.
Make a note of different models of problems: In the abovementioned categories of LR sets, note down the different models of problems that you come across during the course of your preparation in a separate book. Also note the trick to solve those questions such that you can revise it later. Use stickies, if needed. Revise the book from time to time, preferably before each mock test you take. That way you will be able to recall if you come across a similar question in the mock test and hopefully, solve it quickly. In fact, I had made a similar book for Quant as well, where I noted good questions that I came across during my preparation topicwise. It really helps if you revise it regularly!
3. Answer options wide or close ?
Obviously, solving DI sets quickly means often you make a lot of approximations, this may sometimes lead to a situation where your answers is in between two options. You may then have to start over again and do accurate calculations. This may lead to a lot of time wastage. Avoid such questions in the first round if you know the options are very close. It's okay to solve only a few questions in a DI set. Negatives hurt.
4. CBD or NOTA:
If one of the options is Cannot Be Determined (CBD), it becomes a question of Data sufficiency, and sometimes can be quickly solved if you know that one of the requisite data point is not provided in the question. Your answer becomes CBD in that case. If one of the options is None of the Above (NOTA), those who may have solved a few DI or QA questions may agree. Once you get an answer that is not there in the options given and one of the options is NOTA, you are never satisfied and tend to redo the question and end up wasting time. In such a case, it is better to avoid such a question in the first go.
At the end of the day, the only way to over your phobia is to go ahead and solve as many different types of Data Interpretation sets as possible to be familiar with them. Try and categorize the Data Interpretation sets into different kinds and make a note of all these sets and the trick to solve them in a notebook if possible. Revise this book from time to time or before you give every mock, it will help you in the exam.
5. Practice!
I know it's a cliche but it is more important than anything else. It doesn't mean you just practice anything and everything. Work on your identified weak question types to be comfortable with them, and practice questions you can solve to improve your speed further. For example: My weak area initially was cubes and truthliar type questions. I worked on it and by the time I gave my CAT examination, I could solve them accurately and fairly quickly too. It may be difficult to work on question types that you are weak on. At times, you will find boring to solve them. But the more you work on them, the better you will get.
Remember:
"Don’t practice until you get it right. Practice until you can’t get it wrong."  Unknown
All the best!

Could not open the link (showing bad gateway error ) given for past CAT DI LR questions ! Could any one be of any help?

@sayanisaha Thank you. Updated the links.