In a recent blog, my colleague worries about the tinkering of the cutoff marks of the JEE exam. JEE is the exam which secures you admission to the prestigious IIT for the undergraduate program. GATE is the exam which secures you admission to IIT/IISc for the graduate program. Roughly 3 lakhs and 2 lakhs write JEE and GATE, respectively and apply for around 4000 undergraduate and 2000 graduate seats, respectively. Thus, it is the top 1% in each exam who finally gets admitted in IIT/IISc.
In 2006, the cutoff in each subject for JEE was based on the average minus one standard deviation. In 2007 and 2008, it was based on the 20 percentile such that one has to score in the top 80 per cent in each of the three subjects to be considered for admission. In JEE-2009, the first cut-off will not be at the 20th percentile, but at the average score in each subject. Considering the distribution of the marks in JEE is a Weibull distribution, we know that the average does not correspond to the 50 percentile. The cut-off formula is changed just based on public criticism. For example, when the cutoff was based the 20th percentile in 2008, they corresponded to just 5, 0 and 3 marks in math, physics and chemistry, respectively. This raised a hue and cry that someone who scores 0 in physics but enough in mathematics and chemistry such that the aggregate exceeds the overall cutoff would get admitted. Therefore, it was changed to the “average” marks in each subject. There is absolutely no consensus whether sectional marks should be or not be used for cutoff.
This kind of confusion and uncertainty has significantly affected the sister exam, GATE. GATE moved from a descriptive + objective exam to purely an objective exam after a detailed analysis of the marks obtained by the candidates showed that the relationship between marks obtained in the objective section of the paper with the marks obtained in the descriptive section of the paper was linear. GATE score was introduced in 2005 to differentiate candidates who secure between average plus one standard deviation to average plus seven standard deviations. However, this was the most misunderstood parameter even among my colleagues. A student with a GATE score of 700 was thought to have scored more than twice that of a person who scored 300. Actually, GATE score of 700 corresponds to average + 5 standard deviations while 300 corresponds to average + 1 standard deviation. I am glad that GATE has decided to give the actual marks obtained by each candidate, in addition to the GATE score, percentile, All India rank, starting this year (2009).
One thing that I have been pushing for is the introduction of sections in the GATE paper. For example, the chemical engineering paper is roughly divided into seven sections of roughly equal weightage. Math, Fluid Mechanics, Reaction Engineering, Heat and Mass Transfer, Process Control, Process Calculations and Process Economics/ Industry with near equal distribution of marks in each section. There is no faculty in IISc who does research in the last four topics. Therefore, a candidate who secures high marks in the last four sections and nothing in the first three may still qualify in the top 1%, get admitted and find no one doing research in his/her favorite field. This problem is more acute in Mechanical, Civil and some other branches of engineering where the distinctions between the sections are even more drastic. Why can not GATE give marks obtained by the candidate in each section? The particular department in IIT/IISc can then choose which section should be given more importance? It is already done in CAT/GRE where marks in each section are given and the admitting department/institute makes the choice. It is not done because of the problem encountered in JEE. Should each section have a cutoff? If so, should it be based on 20th percentile, average or the 80th percentile. Which candidate should be ranked higher? One who scores 10 marks in each of the seven sections or one who scores 15,15,15,15, 10,0,0? The former is well rounded while the latter is better suited for your research.
Going back to JEE, the statistical questions filled by the candidate when he writes the JEE exam shows that 98% underwent coaching (I think the other two percent lied) and 80% are from an urban population. It is time that JEE is significantly modified to allow less privileged people (who can not afford the coaching) to qualify in the exam. I know that one of the measures that is being thought of is to only allow candidates who have represented the country in the (Math/Physics) Olympiad OR secured an average plus two standard deviations in their respective board exam to write JEE. Because most of the board exams follow a normal distribution, only the top 2.5% will
be allowed to write JEE. JEE will not be an objective exam (i.e., multiple choice questions) but will include several descriptive questions with marks ranging from 1 to 10 for each question. Subsequent to this exam, JEE will announce the marks in each subject for every student that took the exam. The departments in each IIT will decide the weight to each subject. The candidate then decides which branch to apply and to the IIT that (s)he likes. Computer science may give 60% weight to marks in maths and 20% weight each to physics and chemistry. The maths department in IIT may give 90% weight to marks in maths and the candidate can join for the Integrated M.Sc (Maths) there.
How does it help? There are two independent studies that show the performance of the student in the B.Tech directly correlates with the marks obtained in the board (12th) exam. Similarly, one study shows that there is a direct correlation between the performance in the B.Tech class to the performance in M.E/M.Tech in IISc. No such correlation exists with the JEE/GATE rank. The department of IIT/ IISc gets to choose the candidate they want depending on the weightage they assign to each section.
However, until significant changes are made to the entrance exams, we should be content that both the exams are conducted fairly without any political or other influences.
In 2006, the cutoff in each subject for JEE was based on the average minus one standard deviation. In 2007 and 2008, it was based on the 20 percentile such that one has to score in the top 80 per cent in each of the three subjects to be considered for admission. In JEE-2009, the first cut-off will not be at the 20th percentile, but at the average score in each subject. Considering the distribution of the marks in JEE is a Weibull distribution, we know that the average does not correspond to the 50 percentile. The cut-off formula is changed just based on public criticism. For example, when the cutoff was based the 20th percentile in 2008, they corresponded to just 5, 0 and 3 marks in math, physics and chemistry, respectively. This raised a hue and cry that someone who scores 0 in physics but enough in mathematics and chemistry such that the aggregate exceeds the overall cutoff would get admitted. Therefore, it was changed to the “average” marks in each subject. There is absolutely no consensus whether sectional marks should be or not be used for cutoff.
This kind of confusion and uncertainty has significantly affected the sister exam, GATE. GATE moved from a descriptive + objective exam to purely an objective exam after a detailed analysis of the marks obtained by the candidates showed that the relationship between marks obtained in the objective section of the paper with the marks obtained in the descriptive section of the paper was linear. GATE score was introduced in 2005 to differentiate candidates who secure between average plus one standard deviation to average plus seven standard deviations. However, this was the most misunderstood parameter even among my colleagues. A student with a GATE score of 700 was thought to have scored more than twice that of a person who scored 300. Actually, GATE score of 700 corresponds to average + 5 standard deviations while 300 corresponds to average + 1 standard deviation. I am glad that GATE has decided to give the actual marks obtained by each candidate, in addition to the GATE score, percentile, All India rank, starting this year (2009).
One thing that I have been pushing for is the introduction of sections in the GATE paper. For example, the chemical engineering paper is roughly divided into seven sections of roughly equal weightage. Math, Fluid Mechanics, Reaction Engineering, Heat and Mass Transfer, Process Control, Process Calculations and Process Economics/ Industry with near equal distribution of marks in each section. There is no faculty in IISc who does research in the last four topics. Therefore, a candidate who secures high marks in the last four sections and nothing in the first three may still qualify in the top 1%, get admitted and find no one doing research in his/her favorite field. This problem is more acute in Mechanical, Civil and some other branches of engineering where the distinctions between the sections are even more drastic. Why can not GATE give marks obtained by the candidate in each section? The particular department in IIT/IISc can then choose which section should be given more importance? It is already done in CAT/GRE where marks in each section are given and the admitting department/institute makes the choice. It is not done because of the problem encountered in JEE. Should each section have a cutoff? If so, should it be based on 20th percentile, average or the 80th percentile. Which candidate should be ranked higher? One who scores 10 marks in each of the seven sections or one who scores 15,15,15,15, 10,0,0? The former is well rounded while the latter is better suited for your research.
Going back to JEE, the statistical questions filled by the candidate when he writes the JEE exam shows that 98% underwent coaching (I think the other two percent lied) and 80% are from an urban population. It is time that JEE is significantly modified to allow less privileged people (who can not afford the coaching) to qualify in the exam. I know that one of the measures that is being thought of is to only allow candidates who have represented the country in the (Math/Physics) Olympiad OR secured an average plus two standard deviations in their respective board exam to write JEE. Because most of the board exams follow a normal distribution, only the top 2.5% will
be allowed to write JEE. JEE will not be an objective exam (i.e., multiple choice questions) but will include several descriptive questions with marks ranging from 1 to 10 for each question. Subsequent to this exam, JEE will announce the marks in each subject for every student that took the exam. The departments in each IIT will decide the weight to each subject. The candidate then decides which branch to apply and to the IIT that (s)he likes. Computer science may give 60% weight to marks in maths and 20% weight each to physics and chemistry. The maths department in IIT may give 90% weight to marks in maths and the candidate can join for the Integrated M.Sc (Maths) there.
How does it help? There are two independent studies that show the performance of the student in the B.Tech directly correlates with the marks obtained in the board (12th) exam. Similarly, one study shows that there is a direct correlation between the performance in the B.Tech class to the performance in M.E/M.Tech in IISc. No such correlation exists with the JEE/GATE rank. The department of IIT/ IISc gets to choose the candidate they want depending on the weightage they assign to each section.
However, until significant changes are made to the entrance exams, we should be content that both the exams are conducted fairly without any political or other influences.
3 comments:
Very good idea.
This should be implemented.
I am/was good at Mathematics and as a consequence got a decent rank in JEE. I was quite poor at Chemistry. I barely managed to clear the cutoff in Chemistry and have landed up with a department whose main forte is chemistry and its allied subjects. I am not getting to do something I am really good at. This is a very good idea. More than welcome and refreshing to see some changes being made in this direction.
Being a current IIT undergraduate, from my personal experiences, I believe that a majority of the students might be good in a particular topic but they would not be very sure on the fact that they would want to continue with research in that particular field for the next 5 - 10 years> Hnece, I feel that the differentiation between the subjects in JEE and asking a student to take up a field in which he is good at (along with the fact that he is not sure whether he is _interested_ in that) might not be a very good idea.
Moreover, a distinct majority of the 80% urban population write JEE because of the herd mentality and hence, they themselves would not have a very clear setting for the future at the time of JEE counselling.
P.S. As for differentiating between sections in GATE, I completely agree with you because 3 -4 years of a technical degree is a good time to finalize your areas of interest.
i would like to comment on your last observation that m.tech marks are in correlation with b.tech marks whereas gate marks are not.Being a gate aspirant i feel that objective examination preparation style as well as time factor considerations are quite very much different than that for university level subjective examination.Which might be a reason for discriminate result.
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