The half-life of knowledge

| By Professor Tan Eng Chye |

“Teach a person to fish, and you may feed them for three-and-a-half years” may sound less inspiring than “Teach a person to fish, and you feed them for a lifetime”, but the former more accurately reflects the current realities of tertiary education.

Breaking news travels at warp speed, accelerated by social media and instant messaging. In a matter of minutes, news can reach the four corners of the world. Such interconnectedness highlights the leaps made in information technology over the years while underscoring a persistent and inexorable phenomenon – the reduction of the half-life of knowledge. 

The half-life of knowledge, coined by Fritz Machlup in 1962, refers to the amount of time elapsed before half of the knowledge in a particular field is superseded or becomes obsolete. Given the speed with which knowledge develops and is shared, it is perhaps not surprising that this value is ever decreasing in many fields.

This phenomenon raises fundamental questions about our university degree programmes. How should a fresh graduate, filled with aspirations to change the world, deal with the harsh reality that a significant portion of their undergraduate training may be rendered irrelevant by the simple passage of time?

Distilling a degree programme is one possible, albeit drastic approach. We can consider equipping students only with evergreen core domain concepts. This training should take less time than our current degree programmes. As and when students require specific new knowledge, or need to upgrade existing knowledge, they can take short courses to bridge knowledge gaps and meet their professional needs. This type of “just in time” learning, also known as micro-credentialing, helps to circumvent the shortened half-life by injecting cutting-edge knowledge at just the right time. 

Another less disruptive approach is revitalisation. We can maintain the current degree programme structure, but provide avenues for graduates to return to university in the future. Such short stints of study can follow existing models for bite-sized, self-contained courses, or semester-long study periods undertaken with the support of employers. 

One certainty is that university study will cease to be just one stage of life. Instead, “university studies” will become the de facto way of studying, with a person continually refreshing and renewing their knowledge in tandem with or in anticipation of developments in industry, society and the world. 

In anticipation of this, we created the NUS Lifelong Learners Programme (or NUS L3), which  promises a 20-year period of student enrolment, from the point of undergraduate or postgraduate admission. In other words, a graduate of NUS can choose to come back to campus to take courses for at least 20 years from the day of matriculation.


Beyond the way knowledge is acquired, we are also grappling with working in an increasingly VUCA (volatile, uncertain, complex, and ambiguous) world. In such a context, can we continue to hold a siloed view of domain disciplines? In training law students, for example, we would be remiss not to show them basic programming, which can allow them to create customised commands to quickly and easily trawl through databases, with millions of legal records, to identify precedents.

Deep domain expertise is like a laser – a focused beam of knowledge that can cut through dense problems. However, real-world issues are increasingly multifaceted and ill-defined, often lacking a clear vulnerable spot at which a laser beam can be aimed. 

As a mental experiment, consider the challenge of introducing autonomous electric vehicles to a city. This proposition involves urban design, city planning, the law, and engineering for accessibility. We can form a multidisciplinary team of experts, where each member is a domain expert, to tackle the issue. However, in all likelihood, we will encounter misalignment between domains, simply owing to differences in problem-solving methodology, thinking models or even nomenclature.  

If we liken domain training to equipping students with specific lenses through which they can see and focus on information to solve a problem, then interdisciplinarity suggests that we should train students to operate across more than one domain. By educating them in core ideas from multiple domains and providing opportunities to apply their knowledge in authentic settings, students with interdisciplinary training can switch domain lenses as needed, solving problems using novel and unorthodox approaches that transcend domains.

To be clear, we are not advocating for dismantling deep domain training. Rather, we recognise that there is now an indisputable requisite to equip graduates with interdisciplinary knowledge and skillsets. We need both the agile lenses of interdisciplinarity as well as the deep-cutting laser of deep domain expertise. The former trains us to aim and focus the laser, while the latter allows us to cut to the heart of a problem.  

NUS strongly believes in providing interdisciplinary pathways for our students. In 2020, we created the College of Humanities and Sciences (CHS) to provide an enhanced interdisciplinary undergraduate experience for students of the Faculty of Science and the Faculty of Arts and Social Sciences. CHS undergraduates can choose between deep domain training or the flexibility of interdisciplinary training of varying breadth and depth in modules offered by both faculties. Continuing our efforts to pave more interdisciplinary pathways for students, in 2021, we merged the School of Design and Environment and the Faculty of Engineering to form the College of Design and Engineering. More recently, NUS launched NUS College, Singapore’s first honours college offering pathways to more than 50 majors across a half dozen degree programmes. The aim of NUS College, as explained by its inaugural dean, Professor Simon Chesterman, “[is to offer] broad, interdisciplinary competencies that equip students for life, along with the opportunity to dive deep into areas in which you are passionate.”

To quote Charles Dickens, “It was the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness.” Indeed, our experiences with the global pandemic and its effects on education over the past two years have given us the rare opportunity to engage in deep reflection and introspection. Witnessing the breakdown of resistance to adopting and adapting technology for teaching and learning during this time, we should be emboldened to re-examine and revolutionise some of our established, and perhaps outmoded, notions of how to offer higher education.

About the author

nus-president-2019 (cropped)Professor Tan Eng Chye is President of the National University of Singapore. A passionate academic and educator, Prof Tan is a member of the World Economic Forum’s Global University Leaders’ Forum, as well as Singapore’s Future Economy Council, which is tasked with driving the growth and transformation of the country’s future economy.




This article was first published in the Times Higher Education World University Rankings 2023 supplement.