Computerized CAT 2009 - What went wrong?

Any serious B-School aspirant in India will know how revered CAT (Common Admission Test administered by IIMs) is. It is rather aptly considered to be the mother of all competitive exams in India. Not that all competitive tests originated from CAT but that it is by far the most rigorous, time intensive and an outlandishly competitive examination. To me, only IIT's JEE is as competitive, if not more. That said, both these examinations are poles apart. JEE is far too technical whereas CAT is all about precise Math and mind boggling English in a single package.

And now, IIMs have gone a step ahead and wanted to have CAT administered in an online format. And ironically, what transpired makes a very good case study. The CAT committee has stressed that its role in administering the examination at the 105 centres in 32 cities was restricted to preparing questions. That was the objective. IIMs may have wanted to get rid of the test administration part and focus on their institutes and respective programs, which by the way is a great idea. These institutes can focus more on their programs and worry less about the test delivery. And then they chose Prometric as the test delivery partner.

To start with, it is a bold and forward step to plan administer CAT online. I see nothing wrong in this intention. What should take centerstage is to determine if this idea is feasible taking into consideration the limitations of our infrastructure, number of aspirants planning to take the test and above all, the nuances involved with implementing the plans. Do we have the infrastructure to successfully hold an online examination of this magnitude. The answer is evident from this week's fiasco. Not yet!

BITS Pilani administers its admission test online. It has been successful so far. There are a couple of institutes that either conduct their admission test online or outsource the testing process. All this while, an online test is not a test administered on the internet. Computers in a test center are pre-loaded with the examination software and students log on to take the examination. It is pretty much similar to GRE/GMAT with a significant exception that the CAT (pun intended) is not computer adaptive at this point. It is a computer based test as opposed to GRE/GMAT which are computer adaptive. So, what worked for BITS and not for IIMs? Foremost reason would be the number of applicants. About 250,000 (2.5 lakhs) students took CAT in 2008. This year 240,000 students were scheduled to take CAT over a period of 10 days in 105 centers. That is a huge number and it appears bigger when seen in the perspective of our current infrastructure. To pull of a test of this magnitude, Prometric should have had some fool-proof practices in place. It could have organized some mock-CATs (atleast for a price) to see if the computer centers can handle the load. Students would have flocked to avail this offer. In a nation taunted to be a computing superpower, we shouldn't have dearth of anti-virus experts or software. Yet we blame virus attack as a reason for this debacle. A brainstorming session amongst IIMs would have yielded couple of other good fool-proof measures.

Now that CAT is mid-way and the problems are still rampant it is a tricky situation for IIMs. It is an opportunity for IIMs to implement their management practices and clear this mess. But in this debacle, spare a thought for the applicants. Many of them may have been preparing for months and all this stress in the last minute is completely unwanted and unnecessary. I have been going through lot of user comments online and it is a mix of frustration and helplessness. A user complained that his restless neighbor at the test was trying to peep into his computer screen as the neighbor's test hasn't yet begun. Some of them had frozen screens. Some of them were made to run from one center to the other through SMSes. The biggest doubt in the minds of students will be integrity of the test. If the test delivery is vulnerable to viruses, as is claimed, is the scoring vulnerable too? Bringing 'virus' into the discussion opens up a bag of worms (pun again!). Viruses can let outsiders handle a system. If these examination centers have incompetent anti-virus, can outsiders control the software and get to know the questions? I know, it is all a mess!

It will be interesting to see what the future course of action on part of IIMs is. It may be a better idea to start from a clean slate and administer a paper-based test probably 2-3 months down the lane and work on reducing post-processing timelines. One expert suggested administering CAT via the cloud. It could be a good idea for next year. Atleast the crashing part can be taken care of. That said, the main objective for this years CAT should be to ensure that no test taker receives any unfair advantage whatsoever. Only then will this CAT prevail.

English Grammar - Incorrect Usage 1

'Graduated' or 'Graduated from':

Correct Usage: 'Graduated from'.

It is a common error to use 'graduated college'. It should be 'graduated from college'. 'To graduate' is a verb. It can be both transitive or intransitive. A transitive verb takes an object and an intransitive verb doesn't. 

Consider the following example.

Raj graduated from University of Cincinnati.

This sentence uses an intransitive form of 'to graduate', because this verb has no object. 'from University of Cincinnati' is not an object. It is a prepositional phrase that tells you more about where Raj graduated from. But consider this sentence.

Raj graduated University of Cincinnati.

'To graduate' is turned to a transitive verb. The act of graduation is something a school does to a student and not something a student does to school. Schools graduate students. For example,

University of Cincinnati graduated 800 students this year. 

However, in the sentence 'Raj graduated University of Cincinnati', 'Raj' is the subject and 'University of Cincinnati' is the object. So, while 'Raj delighted University of Cincinnati' is gramatically correct, 'Raj' cannot graduate 'University of Cincinnati'.

So, 'graduate from' is correct.

Raj graduated from University of Cincinnati. <>

Raj graduated University of Cincinnati. <>

Best of CAT (Common Admission Test) - 2

This post is the second in the series of my efforts to solve some of the best CAT problems in both theory and programming. It gives me a great pleasure to solve and then verify the answers to some puzzles using C++ or Python and sometimes SAS.

Here is an interesting puzzle that will make you look like a geek (or a nerd - depends on how you look at Mathematics) when you pose it to a group.

Question: There is a certain number X which when divided by Y, where all Y ε [1,10] yields a remainder (Y-1). That is, when X is divided by Y, which takes all values from 1 through 10, the remainder is (Y-1). To be more clear, if X is divided by 10 then the remainder is 9, if X is divided by 9 then the remainder is 8, so on and so forth, if X is divided by 3 then the remainder is 2. The condition should hold good for all numbers from 1 to 10. What is the least number X can take to satisfy this condition? (Hint: X is less than 3000.)

Solution: I programmed this in C++ and it is pretty straight-forward.

The same thing can be implemented in SAS. Let me withhold the answer for now.

Coming to the more important part - to solve this problem by implemting theoritical concepts. This problem pertains to Number Theory. 'Least Common Multiple' doesn't need any introduction. When there are a set of divisors that yield the same remainder (Remainder = 1 in this case), the least number that satisfies this condition =

LCM of those divisors - Common remainder.

By solving, the LCM of numbers 1 through 10 is 2520. Hence the answer = 2520 - 1 = 2519.

All multiples of LCM have the same property. (5040 - 1), (7560 - 1) etc, all have the same property. The objective here is to obtain the least number which satisfies the condition which is 2519. More often than not, confusion prevails in CAT. Also, time is premium in these tests and so the standard method of obtaining LCM may not work well if the divisors are too many or too big. Taking cues from the answers and back solving will be lot helpful. In this problem, it is stated that division by 10 yields 9 which implies that the last digit is 9. That holds the key to solve this problem.

Best of CAT (Common Admission Test) - 1

After a relatively refreshing hibernation, I am back to my web log to write a simple terse article, which is the beginning of a series of such articles that deal with some of the best CAT puzzles I encountered. Computational Mathematics - a domain that I am wildly passionate about, is trying to solve these puzzles in both theory and programming. I will start off with a very simple CAT problem that I encountered sometime back. It was rather interesting and deals with Number Theory, which is one of my favorite areas in Mathematics. I transitioned this logic in C++ and it was truly a good exercise.

It is to determine number of zeros in a given number's factorial. Determining the number of zeros in say, 10! is pretty straightforward. But to determine number of zeros in 100! for example is unwieldly - especially from an examination point of view.

Question: What are the number of zeros in 100!

Solution: To determine number of 0's, it is equivalent to determine how many 10's make up the number. For that 10 = 2 x 5 and (2,5) are co-prime. Hence the number of 10's in number N can be determined by N/5 + N/5^2 + N/5^3+ ..... + N/5^n, as long as N/5^n > 1. '^' stands for exponential operator.

=> 100/5 + 100/5^2
=> 20 + 4 = 24.

Answer: 24

I built this into C++ and the code is intuitive.



Click on this code image to enlarge. Also, edit your headers/libs as necessary.

I will keep posting similar problems (especially from CAT) and I believe this would be mutually beneficial.

ISB in Top 20 (!)

Though I am not a firm believer in MBA rankings, I definitely welcome the Financial Times MBA rankings to place ISB (Indian School of Business) 20th best B-school in the world. ISB ought to receive recognition for its innovation, boldness and strategy. I reserve my judgment if it is really worth to be in the Top 20 and at the outset, it appears to be a bit premature. But, as is true with other rankings, there is no smoke without fire and FT has numbers to give this rank to ISB - which is great.

In recent times, the credibility of MBA rankings has surely taken a beating. Major reason is the mushrooming of sources that issue the rankings. It is surprising to see London Business School in #2, ahead the likes of Harvard and Stanford. But, FT is based in London and so may be they had other assessments too (?). Wharton leads the race for the umpteenth time.

Coming to India and ISB, I believe the diverse class profile, course delivery, cost of the program, duration and the return of investment worked in its favor. The average GMAT for the incoming class is high compared to most other schools in the FT list, which is largely driven by Indian applicants. It is an unprecedented and truly remarkable achievement for the six-year old school. One reason why the IIMs missed the bus, to me, is their over dependence on CAT for admission which eliminates any chance of diversity. I have high regards for CAT (it is the toughest entrance exam to crack) but I feel if IIMs reduce the weightage for CAT (and not compromise on the cut-offs and thus the quality of intake) and implement the currently non-existing requirements like admission essays, work experience in selecting the class, then they (A,B,C) would be on par with the best.

Anyways, it is great to have an Indian school in the list and it only increases ISB's responsibilities to maintain its standards and surge ahead.