Data Interpretation is probably the only testing area in CAT which can be prepared in the least possible time as it is independent of the subject area studied by the candidate at the graduation level.
All it requires is
1) A basic level of understanding of percentage, addition and subtraction, and a thorough grasp over basic arithmetic calculation.
2) A good understanding of various formats of data representations.
3) Reasoning skills
There are basically two types as shown in the figure below. Under these two broad types, you would encounter many types of graphs. The most common types are:
1. Line graphs, 2. Bar graphs, 3. Tables, 4. Three-dimensional graphs, 5. Tournament Questions, 6. Venn Diagrams, 7. Games, 8. Puzzles
Preparation can divided in three phases.
Attain a level of comfort with the basic modes of data representation like graphs, bar charts, pie-charts etc., as given above and at the same time be thorough in Tables up to 20, quick addition and subtractions, comparison of fractions and finding percentage with help of reciprocal of natural numbers like 1/1=100%, ½=50%, 1/3=33.33%, 1/4=25%........... 1/15=6.66% etc.
It is important to note that, to crack a DI question, you need to first understand the question correctly. The second part is clearly the calculation. If you can get a grip on your ability to calculate fast, then all that you need to spend in the next few weeks is to familiarise yourself with the basic concepts and the methods of solving. You should practise at least 25-30 questions of each type of data set.
Start developing ability to solve questions of higher difficulty level. The AIMCATs offered by the T.I.M.E. can be a good source of getting these types of questions. Practice will help student in this phase to develop the essential skill to do CAT questions; but it is not about the number of questions you do for practice but the quality of effort you put in that matters. Do a lot of analysis in understanding the mistakes you made. Mistakes would be of two types, conceptual or a silly mistake.
Now get ready to take some AIMCATs to check your performance. Ideally all three phases can go hand in hand. Since there about three months left, spend time on the phases as listed simultaneously. While you are learning new sets, you can go to the difficult questions from the sets that you have already done. And to add to that, take your AIMCATs every Sunday so that you don’t miss out on Exam Practice.
Select the set to be solved. When you have multiple sets focus on the sets which you can understand and are familiar with. In case if you get stuck then quit and attempt another set of questions.
• Once a set is selected, understand the data. Don't rush towards the questions.
• Understand the Question. What is it that we need to calculate? What is the data required for that and how it can be obtained?
• While solving the question. Look for the simplest method possible and don't calculate things that are not required. At this stage keep an eye on the answer choices. This will help you decide the level of approximation or accuracy required in the calculations.
Remember that you need not solve all questions in a set simply because you have attempted that set. Solve easy and medium questions and then move onto the next set rather than getting stuck on one difficult question.