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Issue of ‘Average of Z scores’

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Dilemma of two syllabi but one qualifying exam:

By Eng. K. A. S. G. Rajakaruna 

 

* Application of Z score method flawed

* Z score attached to respective p value, and not independent

* Dealing with p value the solution

 

The introduction of the new GCE A/L syllabi creates the dilemma of two syllabi but one qualifying-examination every two years because a portion of the student population faces the examination for the third time while others sit it for the first time, under the old and new syllabi, to qualify for university entrance. The failure on the part of the education authorities to make one ranking order is due to the improper application of the Z-score method.

This problem occurs every eight years when new syllabi are introduced and has led to court cases, as in the case of the GCE A/L results, in 2011 and 2019.

This situation occurs due to the Supreme Court judgment in Surendran Vs University Grant Commission, SC APEAL No 480/92 in 1993, which says both groups of students should be treated equally in respect of differences in examinations. Then, it was ‘Average of Percentage Markings’ method in practice. The two examinations, for due 1990 examination, were held in two occasions as 1990 August and 1991 March for the population of candidates due to the war in the North and the East. What is the difference between ‘two examinations under one syllabus’ and ‘two examinations under two syllabi’ in the same field of study for candidates who should get qualified to apply for university admission in the same academic year?

Since the introduction of ‘Average of Z-scores’, as the scaling method for the GCE A/L results in 2001, the dilemma of two syllabi but one qualifying examination came about in 2012 and 2020. It is clear that the introduction of ‘Average of Z-scores’ method has led to confusion. The problem is bound to recur in 2028 as well because the education authorities have failed to work out a solution, in keeping with the Supreme Court judgment, since 1993.

The wrong practice of treating differently the candidates who sit the GCE A/L, in the same year, continues against the 1993 SC ruling.

When the problem resurfaced in 2012, the University Grants Commission (UGC) admitted that the 2011 GCE A/L candidates must be treated as one population, but failed to convince the judiciary as per the SC (FR) case No. 29/2012. Delivering the SC judgment, the then Chief Justice Shirani Bandaranayake accepted the UGC argument as a mere statement.

The SC decided that two examinations, even in the same year, formed two distinct data populations, in its judgment of case No. SC(FR) 29/2012. It was only for the purpose of having two separate sets of data to calculate two sets of Z-scores. It is correct technically.

But, instead of complying with the SC rulings, in 2012 and 1993, the UGC has adopted the average of composite percentage, according to its letter, dated 8/4/2019, issued before the 2019 August examination, held under two syllabi. The prediction of the performance of candidates, facing the examination, based on the data of past five years performances, does not make sense because there was no relationship between two sets.

Indexes used as regards the GCE A/L results, according to the field of study, are flawed.

‘Average of Percentage Markings’, as well as the ‘Average of Z-sores’, are not technically correct terms defined and calculated, though in use. They are the two sides of the same coin as regards evaluations and rankings answer scripts. This may be the reason why ‘Average of Percentage Markings’ has been abandoned.

Dealing with p value is the solution and technically correct practice.

The application of average of Z- scores as the index is technically wrong for two reasons:

1. There is no such thing as ‘Average of Z-scores’. Instead, it is the pooled Z-scores which could not be calculated out of data of relative numbers produced in examination paper markings.

2. The combined-subject effect in the same field of study is not the sum of each subject markings therein.

More importantly, it not fair to work out countrywide rankings with only one combined-subject effect of candidate without considering other factors hindering and enhancing the subject effect unevenly, possibly throughout the country.

Z-scores is not independent and has bearings on p values. The application of average of Z-scores requires the continuation of Z-score method as per the use of respective p value under the normal and standard conditions regardless of the nature of data produced under the old and new syllabi and with data with uneven effect as per the case at hand.

Up to the marking of answer scripts, the management of each subject is independent. The probability of combined effect of independent events is the product of each event, as per the case-combined-effect of subjects in the field of study concerned.

Computer software is available to calculate respective p value, given that the Z values are calculated out of unavoidable percentage markings at examinations. It saves time and money and makes the exercise of ranking candidates in single order fair.

The proposed method p values of paper marking and combined p value according the field of study guarantee the following:

1. Different subject evaluation markings become comparable and convertible to read again as percentage markings.

2. Combined effect p value is read as single-subject p value as number between 0-1. P value could be converted into percentage figures for easy of understanding.

3. Intertangling of marking of different subject in combing is avoided.

4. Marking of dominant subject in the field of study influences rankings.

5. Any number of subjects could be considered as the field of study

6. Equal performances in all the subjects guarantee admission to professional degree programmes.

7. Relatively high performance in one of the subjects enables selection to particular degree programmes where knowledge of the high scoring subject matters.



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Opinion

Mrs Paripooranam Rajasundaram- A Gracious Lady

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I first came to know Mrs Pariapooranam Rajasundaram, who was born in Singapore on October 25, 1935 while serving a short stint in Jaffna with police intelligence. Her late husband who called her “Pari” was my very close friend, Mr. Vaithilingam Rajasunderam, the former principal of Victoria College, Chullipuram who was introduced to me by my friend and police batch mate, late Tissa Satharasinghe, who was the Personal Security Officer, to the late Mr T.B. Ilangaratne in 1971.

Mrs Rajasundaram was blessed with three sons and a daughter and several grandchildren and can be truly described as a very faithful spouse and dedicated mother, mother-in-law, grandmother and a great grandmother to the family of which she was matriarch.

My short spell in Jaffna in 1973 brought me closer to the Rajasunderams who celebration their 25th wedding anniversary in 1974. Theirs was an open house and my wife and sisters too came to know them well.

Mrs Rajasundram and her husband were good hosts and his assassination was a shock to all of us. It was then she became part of our family as she lived with us briefly till she obtained a UK visa to join her daughter and son-in-law there.

Many years later when she was living in England, I had joined KLM Royal Dutch Airlines and my family used to spend vacations with them in Cockfosters in North London. Mrs Rajasundaram treated us to sumptuous meals lavishing attention on us. She was very fond of my wife and two children and had a heart of gold. A devout Hindu she never failed in her religious obligations, lived within her means and was never greedy for what she could not afford. She firmly believed in being patient and willingly gave to those in need.

She was a lady who was selfless, full of compassion, kindness, humility, gentleness, patience, very virtuous, and full of love and character. I can say of her: “People may forget what you did, but people will never forget how you made them feel!”

My prayer as a Christian is that God grants you eternal rest.

NIHAL DE ALWIS

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Opinion

Independence celebrations for whose benefit?

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Celebrating what? Bankruptcy, corruption and nepotism to name a few. Surely isn’t there one MP among 225 who feel we have nothing to celebrate. We say we cannot pay govt. servants’ salaries in time, the pensioners’ their entitlements. A thousand more failures confront us.

In our whole post-independence history such a situation has never arisen. We should be mourning our lost prestige, our lost prosperity our depleting manpower. Our youth in vast numbers are leaving the country for greener pastures. We should be conserving every cent to live, not to celebrate a non-existent independence. We should be mourning, walking the streets in sack cloth and ashes in protest at this wanton waste of money by an irresponsible government.

I can’t understand this mentality. The forces are also our young men who feel for their fellow men and women. Maybe their lot is a little better than the rest of us. But how can you order them to go parade? They cannot refuse. It is an unwritten or written code that they have to obey orders without question. I feel sorry for them. All that spit and polish – for whose benefit? Definitely not ours. We will be mourning in silence in our homes.

Padmini Nanayakkara.

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Opinion

Aftermath Of Mr. Ranjan Wijeratne’s Assassination

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It was on Saturday March 2, 1991 when that fateful LTTE bomb blast shattered the life out of Mr. Ranjan Wijeratne, Minister of Plantations and Deputy Minister of Defence, in front of the Havelock Road University Women’s Hostel opposite Keppetipola Mawatha.

Mr. Wijeratne used to take the same route from home to office every day. The LTTE had monitored his movements and found that it would be easy to target him on his way to office from a strategic point after receiving the information of his departure from home.

The LTTE targeted his vehicle right in front of the University of Colombo Women’s Hostel opposite Keppetipola Mawatha. The suicide bomber crashed into the Deputy Minister’s vehicle and killed the Minister instantaneously.

I had dropped our elder son at Royal College for scouting and then went to the public library to return some books and borrow new ones. After having done that, I was returning home when I saw a large cloud of black smoke going up from somewhere on Havelock Road. As I neared Thummulla junction, a university vehicle (I was Registrar of the Colombo University) was going in the opposite direction.

I stopped it and asked the driver what had happened. He said the Shanthi Vihar restaurant at the Thummulla had been set on fire. The police did not allow vehicles into Havelock Road from Thummulla. I parked the car on Reid Avenue between Thummulla and Lauries Road and walked down the Havleock Road to see what exactly had happened.

As I got onto Havelock Road, a policeman accosted me and told me that I cannot be allowed to proceed. Fortunately, at that moment the OIC of the Bamabalapitiya Police station, Mr. Angunawela, came to that spot and recognizing me told the police constable to allow me to proceed.

As I walked down I saw the damage caused. But there were no signs of any vehicle or any dead bodies as the police had got everything removed. There was a large gaping hole on the road where the blast had occurred. But immediately this was filled up and that section of the road carpeted.

I do not know who had ordered it and why it was done in such a hurry. There were pieces of human flesh hanging from the overhead telephone wires. The blast had also affected the house in front where there was a P& S outlet and a lady who had come to buy something had got her eyes blinded by the shrapnel thrown by the blast.

The parapet wall and the Temple flower (araliya) trees that had been grown just behind the wall were all gone. As I went into the hostel, I saw that the front wall of the hostel building badly damaged. When I went in the girls in the hostel were looking terrified and shivering with fright.

Two of the undergraduates who had gone out of the hostel as they had to sit an examination in the university had got very badly injured and they been rushed to the national hospital. Later one girl who was from Kobeigane, a remote village in the Kurunegala area, succumbed to her injuries. The university paid for her funeral. The security guard who had been close to the gate was thrown up and landed back on the ground. Fortunately, he had no injuries other than feeling groggy.

The next job was to evacuate the hostelers from the building. I telephoned the university office and found the Senior Assistant Registrar in charge of examinations was in office. I told her what had happened and to come to the hostel in a van. Thereafter both she and I packed all the hostelers in the van and sent them to the Bullers Lane Women’s hostel. This was done in three trips.

On inspecting the damage done to the hostel I thought the building would have to be demolished and a new building constructed to replace it. However, I contacted an Engineer, Mr. Upasena, at the Central Engineering Consultancy Bureau (CECB,) who came, inspected the damage to the building and stated that he will get it repaired to be stronger than what it was.

He stated that it might cost around Rs, 20,000/- to get the repair done. I contacted NORAD and they agreed to give the funds required for the repair and renovation. Mr. Manickam from NORAD came and inspected the building and agreed to get much more done than what we wanted repaired and renovated. The repair and renovation were done very quickly and the hostelers were able to move in again.

The reopening ceremony was attended by the then Ambassador to Norway, Mr. Manickam and the Vice-Chancellor. The Vice- Chancellor thanked the Ambassador, Mr. Manickam and the CECB for getting the hostel repaired and renovated to be used again. He never mentioned what I had done to get this hostel repaired and habitable again. That is gratitude!

HM NISSANKA WARAKAULLE

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