Month: October 2014

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Data Interpretation – Strategy

When attempting a test like the CAT, a fair number of people follow the (mindless) strategy of “attempt question 1, move to question 2 only after that is done, then question 3…” and so on, often failing thereby to see all the questions. One should remember that one need not win every single battle to win the war. Given that most people (even most people who will eventually make it!) will not attempt all the 100 questions, your “shot selection” becomes very crucial. You need to recognise – as Rahul Dravid used to so elegantly – which balls to hit and which ones are best left alone, and the faster you can judge this the better.

This becomes all the more crucial in the “set-based” questions (DI, LR and RC) as it generally takes significantly longer to judge these. A typical singleton question (such as a parajumble or remainder or PnC or vocab-based one) can be weighed in 20-30 seconds, and judiciously left without feeling too bad about it. But a set can take up to 3-4 minutes just to understand in detail; and if after spending so much time you realise that you have not been able to decipher it, it can induce a panic.

In the past 5 years, there were 30 questions in each section and there would be around 9-10 questions each (or 3 sets each) of DI or LR. This year, it is likely that there would be 4-5 sets, and as many as 15-18 questions, of each. This means that, as in days of yore, your choice of which sets to attempt first could become crucial. In this post, then, I will try to look at possible mechanisms and criteria to help in the decision-making process (as always, this is indicative and you will have to adapt it to your own areas of strength and weakness) so that you can pick and choose which sets to attack first without actually getting into the nitty-gritty details.

Here are some questions you could ask yourself:

1) Is the given data in a familiar form or in an unfamiliar or haphazard state? And is it precise or ambiguous?

If the data provided is in a standard table / line graph / pie chart and is complete and precise, then even if there is quite a lot of data it should still be very manageable. However, if

  • the data is provided in an unfamiliar form – a histogram, a scatter-chart, a cumulative table, or some even more esoteric format (which means you would require an inordinate amount of time just to understand how to interpret it properly)
  • there is some data missing (which means solving the question might entail a lot of pre-work)
  • the data is not precisely readable, such as a bar- or line-graph where the values can only be approximately estimated to around 5-10% accuracy (which means that even with your best efforts accuracy cannot be guaranteed)
  • the data is presented as a caselet (which means you might have to spend precious time at the start to bring it into a manageable form)

then it might be worth leaving the set for later.

2) Is there additional data provided in the questions?

I’ve observed that a lot of people base their judgement of the difficulty level of a set solely on the pre-information before the questions. In my opinion, though, the questions are almost always worth a dekko; if they are straightforward queries like “Who is sitting next to Mr Sivaramasubramanian?” or “In which year is the profit of Megahard Corporation the maximum?” or “How many people failed in maths?” and the options are not of the “Cannot be determined” flavour then it is a pretty fair indicator that the set is going to give you definite answers in one go.

But if you see questions such as “If Germany defeats Brazil 7 – 0 in the final round*, then who will end up in 3rd place overall?” or “if in 2014, Froogle reports a 10% growth in sales and an 8% growth in costs over 2013, then what will be their percentage profit in 2014?” or even more flagrantly evil question-types like “Which of the following cannot be true” giving three statements and options like “I and II only”, “All of I, II and II” and so on (which effectively means you have to solve 3-4 questions for the price of one), then I would recommend you skip lightly on to the next set and return later.

* This example is a work of fiction and any resemblance to any real-life match is purely coincidental. 

3) Does the set lean more towards the calculative or the reasoning based?

This can be a powerful decision point, depending on your skill-sets. A set which involves intensive calculation is unlikely to go out of its way to confound you with traps, while one which involves simple numbers will often require careful reading and weighing of alternatives. (Personally, calculation is something of a strength for me and hence I choose to do the calculative sets relatively early on, but as I said earlier, this decision has to be based upon your knowledge of your own strengths and weaknesses.)

4) How far apart are the answer choices?

This is a useful question to ask yourself when deciding between two calculative sets. If the answers are far apart – on a percentage rather than absolute basis, mind you! – then you can approximately fairly wildly and still arrive at a correct answer confidently. (For example (3, 7, 12, 18) or (35.7%, 52.8%, 88%, 122%)) However if the answers are close together, then you calculations must needs be carried out with nit-picking accuracy and this will affect your speed as well. (For example (62375, 62525, 62845, 63635) or (35.7%, 36.8%, 38.7%, 39.9%))

5) How many questions are there in each set?

If the sets are similar on the above parameters, then this could be a tie-breaker – a set with 4 questions will give you more value for money (i.e. more marks as a result of the time spent on it) than a similar set with 3 questions.

Try and apply the above criteria to a set in real-time, under test conditions. An excellent case-study would be the DI-LR section from CAT 2008, which had 7 sets covering a wide range of types and difficulty levels. If possible, in a future post I shall try to do a video analysis of the same and roughly demonstrate how one could have approached the section during the test.

regards

J

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CATalysis – 1

A lot of people keep asking me “How should I analyse a SimCAT?” so I felt I should do a post on that.

My observation is that most people write a test, then quickly check the answers/solutions to the ones they got wrong, and move on. They then wonder why the score doesn’t magically improve over time – after all, they are working so hard and taking so many tests! The thing is, taking a lot of tests, by itself, is not enough – one needs to identify areas of improvement and consciously work on them. So how does one proceed to do this?

The first step is the easiest (and consequently everyone does it mindlessly) – take the test, within the prescribed time limits. See the score if you like (but don’t check the correct answers just yet!)

Then, after a short rest break, attempt the test again without time limits. This will tell you which questions you were genuinely clueless about and which ones you lost out on solely because of the time constraints (in other words, it will help you identify the bottleneck in your preparation – conceptual clarity or speed). It will inform the first phase of your analysis below. After this exercise, go to the answer and explanations. And do the following 3 phases of analysis (in any order):

Phase 1: The ones you left (within the timed test)

The results obtained by taking the test a second time without time limits would guide you in this analysis. Identify which questions turned out to be easy, but which you ended up leaving for some reason or another. The two main reasons a question would go unsolved are

(a) You never got round to seeing it: in this case, the blame is squarely on your shoulders. Leaving questions unseen is extremely bad practice. Make sure that, during the 170 minutes available, you have managed to at least read every question and consciously decided whether or not to attempt it on its merits.

Understand that the broad, superficial topic should not be the only criterion for attempting or leaving a question. Don’t leave a question just because “it is from Probability” or “I hate Parajumbles” – you should be capable of attempting a simple question in any and every sub-field within the syllabus. Conversely, don’t attempt a question beyond your skills just because of some flawed logic like “I must do all TSD questions in every paper” or “I will attempt all the LR or die trying”. In analyses, I often found that people skipped questions from an area of discomfort in 3-4 seconds (even with a phenomenal reading/comprehension speed, there is no way they would have read, understood and decided rationally about it in that span of time!), while in other cases the same people spent 6-8 minutes or more struggling with an intractable poser, just because it was from a topic they considered themselves experts at.

(b) You found it incomprehensible or just downright scary: in this case, your analysis needs to identify whether it actually was a tough problem or just masquerading as one. In a 100 question test, chances are that there will be a few questions which are really gruelling; the only intent of these is to test whether you have the presence-of-mind to leave them and move on. But these will be few in number. A larger bunch of questions will look extremely difficult without being nearly as bad as they appear; exams like CAT, XAT and IIFT specialise in these. Identifying these might make a key difference in your scoring patterns and provide a 10-15 mark boost.

Phase 2: The ones you got wrong

Find out, among those, how many of them you goofed up because of silly mistakes, how many were because of misreading the question (as in you failed to understand the English of the question, what it was asking you to find) and how many were because your concepts were unclear (you understood what needed to be found but were unable to hit upon the right logic/formula/concept).

(a) There were lots of silly mistakes: work on focus, on avoiding those lapses of concentration (in one way it is a good thing – it means you can achieve significant score improvement in a short time as your concepts are sound). Examples of this would be taking the diameter of a circle as the radius, forgetting the factor of ½ in the area of a triangle, taking the sum of n natural numbers as n(n-1)/2 instead of n(n+1)/2, writing 3 x 3 = 6, etc.

(b) Understanding was the issue: learn how to identify the language cues in the question, so that in future you would be better equipped to notice the subtle traps and shades of meaning inherent in a well-set question. For example, if the question uses the phrase “non-negative integer solutions” then it should ring a warning bell in your mind; why hasn’t the examiner used the simpler “positive integer solutions”? And immediately the answer should strike you – you need to watch out for the zero as well.

(c) Conceptual clarity was a problem: revisit the relevant topic in your Basic Reference Materials and textbooks and internalise the concept thoroughly so that in future you will be able to apply it properly. For example, if you lost 3 easy marks because you forgot the volume of a sphere or the concept of a dangling modifier or the number of ways to put identical objects into distinct groups, you should chastise yourself mentally and ensure that in future you know everything you need to.

Phase 3: The ones you got right

This is the part of the analysis most people ignore, even the serious ones. I mean, it is right, right? Why bother analysing it? seems to be the thought here. However, there are crucial lessons to be learned here as well. After all, these are the question types you are surely going to attempt on the D-day as well, so it behooves you to be as efficient as possible in them.

(a) Questions you got right by a fluke: ensure that, in the future, you will know the correct logic for these. You don’t want to rely on luck in the real thing, do you?

(b) Questions you got right by a valid logic: it is always great to get 3 marks, no doubt, but if you spent 7-8 minutes on them then that takes off some of the sheen; the price is a little too high. Try to seek a better, more efficient way to do them, reduce the effort and time spent. And what of those which took only 2 minutes? Even there, see if you can reduce it to 1.5 minutes? 1 minute? 40 seconds? Because that will give you more time to spend on the other, tougher questions. Start with the assumption “However good I am at this, I can always get better”, let that be a cantrip guiding your preparation.

In my next “strategy” post I will try to look at a broader analysis; how to find your strengths and weaknesses and use them to optimise the order of attempting questions.

regards

J