How to do well in the GRE exam
GRE, unlike most exams you faced till date, tests
what you can learn and not what you have already learnt.
They test your verbal skills to see whether you can understand and present
material at a given level of difficulty. They test your basic math
skills to find out whether you can do the simple back-of-the-envelope
calculations needed in any advanced study for a quick check. Finally,
they test your logical abilities only to check how coherently you can
present and defend your findings.
ETS spends a lot of time, money and intellect on choosing the questions
and the test format. As a result they do not easily deviate from
what they have already found.
As you can see from there, ETS virtually fixed the ratio of their questions
in each category. Let us look at a simpler example to understand
the relevance of this analysis.
If you are equally weak in "fractions" and "ratios"
what should you do to maximize your scores? Spend equal amount of
time on both. Right?
...
Wrong!!!
You have only 0.18% of the questions from the fractions and 8% of the
questions from the ratios. So, you should spend around 50 times
more time on the ratios!
This is a very significant point. Don't underestimate its importance
in maximizing your scores.
You have two ways of preparing effectively. One way is to use all
those patterns that you got from the site and devise a study plan.
Identify questions from each category in that ratio and work on them.
Well, I will tell you an easier way of doing it. Prepare from original
GRE papers where these ratios are maintained!!
ETS had released a book called "The BigBook". It has 5000
and odd questions from actual GRE. Well, that is an overkill.
But, these are the perfect tools to get used to the kinds of questions
asked in the actual GRE.
Now that you know how to master the types of
questions asked in the GRE, you should master the type of exam the GRE.
GRE is a CAT or what they call: A computer adaptive
test.
You should first understand the term computer adaptive test before you
can master it.
CAT Defined
A computer adaptive test or a CAT basically is an
exam that changes its level of difficulty based on the user's performance.
Now, there was nothing like "an adaptive test" before the computer came
along. The reason is pretty simple.
To conduct that test, some one has to monitor the test takers performance
after each and every question and change the next question accordingly.
This literally means one examiner for one candidate. Obvious impossibility
:-)
Once the computer testing came in to fore, things got a bit simplified.
Computers started monitoring individual's performance during the test.
Let us just see what happens in a true CAT.
How is a CAT conducted?
As soon as the you start taking the exam, the program
takes a medium level difficulty question from its bank and places it on
the screen. Now you basically can either answer correctly or incorrectly.
If you answer it correctly, the next question will be made slightly more
difficult. If you answer it incorrectly, the next question will be made
slightly less difficult. Less difficult questions will carry less marks
and more difficult questions will carry more marks.
Your final marks depends on not only on the number of questions you answered
correctly, but on the number of difficult questions that you answered
correctly. For example, in a PowerPrep GRE exam, in a quantitative section,
I answered first 10 questions correctly and the later all incorrectly.
My score was 220. When I answered first 5 and the last 5 correctly and
the later incorrectly my score was 300.
Though I had answered 10 questions correctly both times, the difficulty
levels varied in each case. We will look at various ways of maximizing
scores based on this aspect in a later chapter.
Now let us look at how a CBT (computer based test) is conducted
CBT defined
A CBT is a test with a programming interface.
It lets you answer a question on the monitor. It has the same set of questions
irrespective of the user. So, you answer the first question and the computer
generates the second one in the list.
It does not change its questions based on your performance. In one word…
...A CBT is a paper based test taken on a computer.
As discussed before, in a CAT, the questions vary based on the performance.
This means that literally each student gets a different question paper.
A lot more work has to be spent in generating the CAT exam.
Statistical research
Tremendous amount of research is needed to prepare
a CAT exam.
The first
and foremost aspect is determining the difficulty level of a question.
An examiner may feel that certain question is very
difficult. But the test takers may find it easy. In addition, an examiner
might be able to distinguish in to 3, 4, or 5 levels.
But CAT needs a lot more layers than that. The best way to arrive at it
is by running trial tests on students with similar back grounds. So, if
only 10% of the candidates get it right it is a very difficult question.
If 90% get it right, it is an easy question.
Note that the percentage is inversely proportional to the difficulty level.
ETS has conducted enormous amount of research on its questions and finally
figured out several difficulty levels. They never explicitly say the number
of levels they divided their questions in to. But my experiments indicate
that they have several.
Second issue that
needs to be settled is the minimum number of questions that the student
is required to answer.
In a paper based test the difficulty levels do not
change and every one answers the same question paper. So, scores can be
directly compared.
In a CAT, the levels keep fluctuating and the candidate needs to get stabilized
and answer some questions at a comfortable level (the guess factor needs
to be accounted for). So, the test maker needs to figure out the number
of questions the test taker should take before the optimum levels are
decided.
One can do this by allowing a student to take both paper based and CAT
tests a number of times. After obtaining a paper based test score, one
can check the number of questions after which CAT scores are stabilizing.
A survey on several students can lead to an accurate number of questions
that are required for each section.
In GRE CAT, the verbal has 30 questions as opposed to the 38 in the paper
based test, 28 quantitative questions as opposed to 30 in the paper based
test and 35 analytical questions as opposed to 25 in the paper based test.
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