Features
Restaging Z-Score Debacle
The release of the Z scores for university admission by University Grants Commission (UGC) has brought thousands of complaints and issues from the students, parents, teachers and other stakeholders into discussion. Some others have vowed to take the issue to courts, expecting a fair and just solution.
Most of the complaints are related to the issue of two different cutoff Z scores for new syllabus and old syllabus and comparisons thereof. It is understood that the solutions proposed to resolve a crisis must not only be fair and legal but also seen to be reasonable for the stakeholders. Print media during the last couple of weeks published several opinions on this issue and the use of Z score for university admission is often blamed as the reasons for these discrepancies. It is time we had a closer look at the problem and baseless allegations against the use of Z-score for university admission. The use of Z-score in place of aggregated marks of the three subjects is, by all means, a better method, which has been amply demonstrated with data and examples and subjected to discussion since its introduction for university admission in 2003.
There is a diverse degree of variability in nature itself and so it is with the humans and their work. The scientific discipline called statistics provides the conceptual and procedural approaches to understand the variability and manage it fairly and equitably. Due to the inherent variability present in question papers and evaluations, it is very well understood that the simple aggregate obtained from the marks of different subjects is not a fair criterion for determining the eligibility for university admission. The degree of difficulty of the question papers in different subjects varies significantly and also there are variations of the aptitude measurement scale in different years. Therefore, it was not possible to have a fixed cut-off mark or simple aggregate solution to determine eligibility for university admission. For example, marks for one subject could have a range from 5 to 70 while the range for another subject spans from 45 to 99. A student who obtained 70 is the best among the lot in the first case and the one who obtained 70 in the second case is a mediocre student. When the simple aggregate is taken as the criterion for university admission, the best student in the first case is treated equally with the mediocre student who opted for a relatively easy subject as in the second case. Within the general assumption that students who sit for these two different subjects have a more or less equal level of competence, the disparity in the relative difficulty of the question papers or evaluation criteria warrants some sort of an approach for standardization. This issue was the theme for a series of discussions in academic circles and despite several advanced methodologies available for standardization, the Z score approach was adopted about 20 years back as the criterion for university admission due to its simplicity, computational convenience, application efficiency and the need for only two parametric estimates for its calculation.
Today, the issue is somewhat different and it is not possible to assume that the students who sat for two different papers in the same subject are having a more or less equal level of competence or they are random picked from the larger population. The first group has sat for the examination for the first time and the other group has at least attempted to pass the examination on one or more previous occasions. This is evident from the number of the first, second and third attempt students in different disciplines. In exploring a solution to this present problem, the underlying assumptions made in calculating the Z score rankings need to be reexamined. One of the assumptions is that the aptitude of knowledge and skills of the student population opting for different subjects or subject streams are not significantly different. This assumption should be validated now because almost all the students who sat the examination under the old syllabus except those with valid medical or other reasons have made a failed attempt to enter university earlier.
Those who qualify from the new syllabus are a group of students who took the examination for the first time. The assumption of equal knowledge and similar competency level and skill background for these two diverse groups introduces an error into the fair selection process. It is not possible to issue a single series of Z-scores for these two groups. Before processing marks, the hypothesis of statistically non-significant difference between these two student groups needs to be validated with at least past data for a period of 5 years. Since this hypothesis cannot be proved, then the degree of dissimilarity needs to be assessed to determine a fair ratio for university admission from these two groups of students and design a quota for these two groups. This is what the UGC has attempted to employ in the selection process, however, higher differences in the cut-off Z scores due to the impact of quota applied for the two groups has led to serious doubts in the mind of those without an in-depth knowledge of the method.
The second issue is whether the relative difficulty of two questions papers in both old and new syllabi is significantly different. The expert opinion is the only choice we have in this decision. If experts believe that the two sets of questions papers are of more or less a same level of standard, then the two results could have been combined into a single data series with only one set of Z scores and cut-off marks. Unfortunately, there is no evidence to show that this option had been explored by the UGC. If the question papers are at significantly different standards, then it is not possible to combine the two results series. Then the question must be asked from the Department of Examinations why the standards were made to be different and a strong justification for such an action. We always advise our students that they should propose a valid statistical methodology before they collect their data for research to ensure the compatibility of data with the statistical techniques to be employed in the analysis. Unfortunately, the Department of Examinations could not stick to this advice and only seeks a statistically valid solution after collecting the data from student examinations.
Without understanding the pertinent facts, some argue that the mistakes made in 2011/12 university admission have been repeated in releasing the Z-scores for 2019/20 university admission. A similar problem indeed arose in 2011/12 admission due to the release of Z scores, combining the results of students who followed the GCE Advanced level under old and new syllabi. However, in 2011/12 university admission, the major issue was the errors made in the calculation of Z scores by the Department of Examinations. That mistake was further complicated due to the release of a single Z score combining the two distinctly different student populations of old and new syllabi as a single group by the UGC. A presidential expert committee was appointed to look into the problem and the mistake in the calculation was quickly identified and corrected. Besides, the need to consider the two student populations of old and new syllabi separately for university admission was proposed and it was later approved by a Supreme Court judgment in a case filed by a group of aggrieved students.
There are few solutions which could have been adopted to avoid the complexity of the problem and misunderstanding among the students, parents and teachers:
a) The easiest approach would have been the designing one question paper for both groups of students sitting the examination under both old and new syllabi giving options to select questions from the areas that had been revised or amended in the new curriculum. It is observed that there have been no major deviations and only minor changes have been made as regards Physics and Chemistry. The relative difficulty level needs to be maintained across all optional questions. Then, it is a single question paper and a single Z score series generated from the results. This should have been achieved at the point of setting of question papers by the examiners with clear instructions.
b) if the two questions papers, although structurally different, are of the same level of difficulty, the results of the two examinations could have been combined and Z scores computed as a single series.
This solution could have been explained to the Supreme Court and concurrence on this approach sought.
It could have been assumed that although the student populations were different, the same level of tests had been administered for both groups and therefore,
c) The most reasonable solution for the problem is to determine the ratios of students admitted to universities for each subject stream and each degree programme separately for old and new syllabus students, and then for each case use the five-year maximum proportion to admit students to universities. Then the total would exceed one hundred since the maximum of both ratios would exceed 100 and a small proportion of students needs to be admitted to each degree programme to avoid any obvious injustice. The use of median value can also be adopted unless there is a positive or negative trend in the ratios. If the five-year values are stationary and have a low variability among years, this becomes a fair solution. In case the five-year values are having a higher degree of variability and an obvious trend, the most recent value should have been the choice. This method of median value was adopted this year and due to the quota being significantly different for different disciplines and degree programmes, the cut-off Z scores have shown many differences for new and old syllabi students. Also, the cut-off Z-scores are significantly high compared to the figures of the previous years due to the application of quota which sometimes 25% of the original 100. This is the reason for the complaints although the method used for selection is in keeping with the ruling of the Supreme Court in 2012.
However, this problem could have been avoided if the two series of Z scores were adjusted as per the quota granted for each series. A simple mathematical computation could have brought the two distributions on a comparable model. The adjusted Z scores are comparable with the figures of the previous years and it would not produce cut-off Z scores which are much different for students in two groups. The confusion created due to the releasing Z scores indicating a different level of access to university entrance in the two different groups could have been avoided with the help of such an approach.
The writer is Former Vice-Chancellor of the Uva Wellassa University and Chairman of the UGC University Admission Committee in 2013/14 and member of Presidential Committee on Z score in 2012 .
Features
Ranking public services with AI — A roadmap to reviving institutions like SriLankan Airlines
Efficacy measures an organisation’s capacity to achieve its mission and intended outcomes under planned or optimal conditions. It differs from efficiency, which focuses on achieving objectives with minimal resources, and effectiveness, which evaluates results in real-world conditions. Today, modern AI tools, using publicly available data, enable objective assessment of the efficacy of Sri Lanka’s government institutions.
Among key public bodies, the Supreme Court of Sri Lanka emerges as the most efficacious, outperforming the Department of Inland Revenue, Sri Lanka Customs, the Election Commission, and Parliament. In the financial and regulatory sector, the Central Bank of Sri Lanka (CBSL) ranks highest, ahead of the Securities and Exchange Commission, the Public Utilities Commission, the Telecommunications Regulatory Commission, the Insurance Regulatory Commission, and the Sri Lanka Standards Institution.
Among state-owned enterprises, the Sri Lanka Ports Authority (SLPA) leads in efficacy, followed by Bank of Ceylon and People’s Bank. Other institutions assessed included the State Pharmaceuticals Corporation, the National Water Supply and Drainage Board, the Ceylon Electricity Board, the Ceylon Petroleum Corporation, and the Sri Lanka Transport Board. At the lower end of the spectrum were Lanka Sathosa and Sri Lankan Airlines, highlighting a critical challenge for the national economy.
Sri Lankan Airlines, consistently ranked at the bottom, has long been a financial drain. Despite successive governments’ reform attempts, sustainable solutions remain elusive.
Globally, the most profitable airlines operate as highly integrated, technology-enabled ecosystems rather than as fragmented departments. Operations, finance, fleet management, route planning, engineering, marketing, and customer service are closely coordinated, sharing real-time data to maximise efficiency, safety, and profitability.
The challenge for Sri Lankan Airlines is structural. Its operations are fragmented, overly hierarchical, and poorly aligned. Simply replacing the CEO or senior leadership will not address these deep-seated weaknesses. What the airline needs is a cohesive, integrated organisational ecosystem that leverages technology for cross-functional planning and real-time decision-making.
The government must urgently consider restructuring Sri Lankan Airlines to encourage:
=Joint planning across operational divisions
=Data-driven, evidence-based decision-making
=Continuous cross-functional consultation
=Collaborative strategic decisions on route rationalisation, fleet renewal, partnerships, and cost management, rather than exclusive top-down mandates
Sustainable reform requires systemic change. Without modernised organisational structures, stronger accountability, and aligned incentives across divisions, financial recovery will remain out of reach. An integrated, performance-oriented model offers the most realistic path to operational efficiency and long-term viability.
Reforming loss-making institutions like Sri Lankan Airlines is not merely a matter of leadership change — it is a structural overhaul essential to ensuring these entities contribute productively to the national economy rather than remain perpetual burdens.
By Chula Goonasekera – Citizen Analyst
Features
Why Pi Day?
International Day of Mathematics falls tomorrow
The approximate value of Pi (π) is 3.14 in mathematics. Therefore, the day 14 March is celebrated as the Pi Day. In 2019, UNESCO proclaimed 14 March as the International Day of Mathematics.
Ancient Babylonians and Egyptians figured out that the circumference of a circle is slightly more than three times its diameter. But they could not come up with an exact value for this ratio although they knew that it is a constant. This constant was later named as π which is a letter in the Greek alphabet.
It was the Greek mathematician Archimedes (250 BC) who was able to find an upper bound and a lower bound for this constant. He drew a circle of diameter one unit and drew hexagons inside and outside the circle such that the sides of each hexagon touch the sides of the circle. In mathematics the circle passing through all vertices of a polygon is called a ‘circumcircle’ and the largest circle that fits inside a polygon tangent to all its sides is called an ‘incircle’. The total length of the smaller hexagon then becomes the lower bound of π and the length of the hexagon outside the circle is the upper bound. He realised that by increasing the number of sides of the polygon can make the bounds get closer to the value of Pi and increased the number of sides to 12,24,48 and 60. He argued that by increasing the number of sides will ultimately result in obtaining the original circle, thereby laying the foundation for the theory of limits. He ended up with the lower bound as 22/7 and the upper bound 223/71. He could not continue his research as his hometown Syracuse was invaded by Romans and was killed by one of the soldiers. His last words were ‘do not disturb my circles’, perhaps a reference to his continuing efforts to find the value of π to a greater accuracy.
Archimedes can be considered as the father of geometry. His contributions revolutionised geometry and his methods anticipated integral calculus. He invented the pulley and the hydraulic screw for drawing water from a well. He also discovered the law of hydrostatics. He formulated the law of levers which states that a smaller weight placed farther from a pivot can balance a much heavier weight closer to it. He famously said “Give me a lever long enough and a place to stand and I will move the earth”.
Mathematicians have found many expressions for π as a sum of infinite series that converge to its value. One such famous series is the Leibniz Series found in 1674 by the German mathematician Gottfried Leibniz, which is given below.
π = 4 ( 1 – 1/3 + 1/5 – 1/7 + 1/9 – ………….)
The Indian mathematical genius Ramanujan came up with a magnificent formula in 1910. The short form of the formula is as follows.
π = 9801/(1103 √8)
For practical applications an approximation is sufficient. Even NASA uses only the approximation 3.141592653589793 for its interplanetary navigation calculations.
It is not just an interesting and curious number. It is used for calculations in navigation, encryption, space exploration, video game development and even in medicine. As π is fundamental to spherical geometry, it is at the heart of positioning systems in GPS navigations. It also contributes significantly to cybersecurity. As it is an irrational number it is an excellent foundation for generating randomness required in encryption and securing communications. In the medical field, it helps to calculate blood flow rates and pressure differentials. In diagnostic tools such as CT scans and MRI, pi is an important component in mathematical algorithms and signal processing techniques.
This elegant, never-ending number demonstrates how mathematics transforms into practical applications that shape our world. The possibilities of what it can do are infinite as the number itself. It has become a symbol of beauty and complexity in mathematics. “It matters little who first arrives at an idea, rather what is significant is how far that idea can go.” said Sophie Germain.
Mathematics fans are intrigued by this irrational number and attempt to calculate it as far as they can. In March 2022, Emma Haruka Iwao of Japan calculated it to 100 trillion decimal places in Google Cloud. It had taken 157 days. The Guinness World Record for reciting the number from memory is held by Rajveer Meena of India for 70000 decimal places over 10 hours.
Happy Pi Day!
The author is a senior examiner of the International Baccalaureate in the UK and an educational consultant at the Overseas School of Colombo.
by R N A de Silva
Features
Sheer rise of Realpolitik making the world see the brink
The recent humanly costly torpedoing of an Iranian naval vessel in Sri Lanka’s Exclusive Economic Zone by a US submarine has raised a number of issues of great importance to international political discourse and law that call for elucidation. It is best that enlightened commentary is brought to bear in such discussions because at present misleading and uninformed speculation on questions arising from the incident are being aired by particularly jingoistic politicians of Sri Lanka’s South which could prove deleterious.
As matters stand, there seems to be no credible evidence that the Indian state was aware of the impending torpedoing of the Iranian vessel but these acerbic-tongued politicians of Sri Lanka’s South would have the local public believe that the tragedy was triggered with India’s connivance. Likewise, India is accused of ‘embroiling’ Sri Lanka in the incident on account of seemingly having prior knowledge of it and not warning Sri Lanka about the impending disaster.
It is plain that a process is once again afoot to raise anti-India hysteria in Sri Lanka. An obligation is cast on the Sri Lankan government to ensure that incendiary speculation of the above kind is defeated and India-Sri Lanka relations are prevented from being in any way harmed. Proactive measures are needed by the Sri Lankan government and well meaning quarters to ensure that public discourse in such matters have a factual and rational basis. ‘Knowledge gaps’ could prove hazardous.
Meanwhile, there could be no doubt that Sri Lanka’s sovereignty was violated by the US because the sinking of the Iranian vessel took place in Sri Lanka’s Exclusive Economic Zone. While there is no international decrying of the incident, and this is to be regretted, Sri Lanka’s helplessness and small player status would enable the US to ‘get away with it’.
Could anything be done by the international community to hold the US to account over the act of lawlessness in question? None is the answer at present. This is because in the current ‘Global Disorder’ major powers could commit the gravest international irregularities with impunity. As the threadbare cliché declares, ‘Might is Right’….. or so it seems.
Unfortunately, the UN could only merely verbally denounce any violations of International Law by the world’s foremost powers. It cannot use countervailing force against violators of the law, for example, on account of the divided nature of the UN Security Council, whose permanent members have shown incapability of seeing eye-to-eye on grave matters relating to International Law and order over the decades.
The foregoing considerations could force the conclusion on uncritical sections that Political Realism or Realpolitik has won out in the end. A basic premise of the school of thought known as Political Realism is that power or force wielded by states and international actors determine the shape, direction and substance of international relations. This school stands in marked contrast to political idealists who essentially proclaim that moral norms and values determine the nature of local and international politics.
While, British political scientist Thomas Hobbes, for instance, was a proponent of Political Realism, political idealism has its roots in the teachings of Socrates, Plato and latterly Friedrich Hegel of Germany, to name just few such notables.
On the face of it, therefore, there is no getting way from the conclusion that coercive force is the deciding factor in international politics. If this were not so, US President Donald Trump in collaboration with Israeli Rightist Premier Benjamin Natanyahu could not have wielded the ‘big stick’, so to speak, on Iran, killed its Supreme Head of State, terrorized the Iranian public and gone ‘scot-free’. That is, currently, the US’ impunity seems to be limitless.
Moreover, the evidence is that the Western bloc is reuniting in the face of Iran’s threats to stymie the flow of oil from West Asia to the rest of the world. The recent G7 summit witnessed a coming together of the foremost powers of the global North to ensure that the West does not suffer grave negative consequences from any future blocking of western oil supplies.
Meanwhile, Israel is having a ‘free run’ of the Middle East, so to speak, picking out perceived adversarial powers, such as Lebanon, and militarily neutralizing them; once again with impunity. On the other hand, Iran has been bringing under assault, with no questions asked, Gulf states that are seen as allying with the US and Israel. West Asia is facing a compounded crisis and International Law seems to be helplessly silent.
Wittingly or unwittingly, matters at the heart of International Law and peace are being obfuscated by some pro-Trump administration commentators meanwhile. For example, retired US Navy Captain Brent Sadler has cited Article 51 of the UN Charter, which provides for the right to self or collective self-defence of UN member states in the face of armed attacks, as justifying the US sinking of the Iranian vessel (See page 2 of The Island of March 10, 2026). But the Article makes it clear that such measures could be resorted to by UN members only ‘ if an armed attack occurs’ against them and under no other circumstances. But no such thing happened in the incident in question and the US acted under a sheer threat perception.
Clearly, the US has violated the Article through its action and has once again demonstrated its tendency to arbitrarily use military might. The general drift of Sadler’s thinking is that in the face of pressing national priorities, obligations of a state under International Law could be side-stepped. This is a sure recipe for international anarchy because in such a policy environment states could pursue their national interests, irrespective of their merits, disregarding in the process their obligations towards the international community.
Moreover, Article 51 repeatedly reiterates the authority of the UN Security Council and the obligation of those states that act in self-defence to report to the Council and be guided by it. Sadler, therefore, could be said to have cited the Article very selectively, whereas, right along member states’ commitments to the UNSC are stressed.
However, it is beyond doubt that international anarchy has strengthened its grip over the world. While the US set destabilizing precedents after the crumbling of the Cold War that paved the way for the current anarchic situation, Russia further aggravated these degenerative trends through its invasion of Ukraine. Stepping back from anarchy has thus emerged as the prime challenge for the world community.
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