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Get to know Joost Kok and discover the invisible power of big data

Enormous quantities of information are collected throughout the world, that could lead to scientific breakthroughs such as new medical treatments. At least, if you can find a smart way to store and analyse the data.

Read more about Professor of Computer Science and Medicine Joost Kok, about research and teaching on this topic at Leiden University and about the impact on society.

Discover the world at Leiden University

Research: battling trillions of gigabytes

The ability to process and analyse large quantities of information at a rapid rate has become a valuable ‘commodity’, including in academia. Whether you are studying something as small as a molecule or as immense as the universe, you will work with big data. Top athletes who save and analyse the data from each training session in order to improve their performance also use data analysis. Joost Kok, Professor of Fundamental Computer Science at Leiden University, is an expert in the field of processing and analysing data. He helps scientists to develop new treatments, aids the government in discovering potential fraudulent health insurance claims and advises the Ministry of Transport on monitoring the condition of bridges from a distance.

Athletes use data processing to perform better.

Medicine, psychology, music, sport, traffic, share trading: these are but some of the many fields that collect and analyse large quantities of data (numbers, text, images, graphics, audio and much more) in order to achieve their goals. Big data is everywhere. Joost Kok: ‘Take large supermarket chains, for example. They register countless factors in their stores: the temperature, when and how many people look happy, and so on. Computers use this kind of data to calculate what a manager can change in the store in order to sell as much as possible.’ IBM estimates that 2.3 trillion gigabytes of data (business and private) are created worldwide each day. ‘Processing, analysing and making this data findable  ̶  what is known as data science  ̶  throws up all sorts of challenges,’ Kok explains. ‘To begin with, all the data you have collected can contain errors. What can you do about that? There are also limits to the capacity of the computers that need to store the data and make the calculations necessary to analyse it. The main thing is to ensure that the computer calculations are as smart as possible. What we do is battle the complexity of data and try to link different types of data, such as images and text.’

Joost Kok is Scientific Director of the Leiden Institute of Advanced Computer Science (LIACS). He and his colleagues conduct research into and give advice on data science. He programmes computers to analyse data as rapidly as possible. This makes him an invisible yet indispensable force behind all sorts of projects that have a major impact on society. Over the last 20 years, Kok has helped conduct research into children’s play in the school playground, detect irregularities in health insurance claims and improve the performance of top Dutch athletes. He is also participating in research on how to make computers calculate in new ways, based on processes that take place in nature.

Research lines: from big data to the molecular computer

Data Science in practice

Joost Kok translates his knowledge of data storage and analysis into many different practical applications. He gives a few examples.

More about Data Science in practice

New search and calculation methods

Joost Kok not only helps academics and businesses store and analyse data, he and his colleagues are also seeking new methods that will make the data more findable and speed up the analyses.

More about New search and calculation methods
‘Scientific breakthroughs thanks to data science’

Teaching: ‘A solid scientific basis’

Joost Kok supervises PhD fellows and teaches Computer Science to bachelor’s students and students at the Leiden University Medical Center. He believes it is particularly important that students acquire a solid scientific basis for their studies. ‘We begin by giving our students a good mathematical grounding. To draw a comparison: we believe that you can drive a car better if you know how the engine works. We then try to make it possible for students to acquire as much practical knowledge as possible.’

Joost Kok along with several PhD students

‘During the programme we work with other departments (Economics and Biology, for example) to produce theses that take all sorts of different approaches. We provide differentiation once the students have completed their bachelor’s degree, offering different master’s programmes in such subjects as ICT and Business, Computer Science and Media Technology. Students are also given the opportunity to gain experience abroad. We have many contacts in China in particular, and we in turn welcome many foreign students.’ After this programme you can follow any number of different paths, says Kok. ‘Computer Science is a relatively young and undeveloped field, and the opportunities are multifold. The knowledge and skill that starters bring to the job market thanks to this programme makes them very desirable.’

More programmes in the field of Data Science

Computer Science : Computer Science has changed society in recent decades. And this is set to continue, because we are only at the beginning of the development of computer technology and artificial intelligence.

Mathematics : You obviously know mathematics from secondary school. But the mathematics that you are familiar with is only a small part of a much more expansive science that is alive and kicking and has a multitude of applications. Study mathematics at university and you will discover just how broad this science is.

Medicine : If you study Medicine, you learn all about the workings of the healthy and sick human body, from molecule to nervous system. You apply what you have learnt to reach a diagnosis or propose a therapy. You are trained as a doctor and learn how to conduct scientific research.

Biomedical Sciences : If you study Biomedical Sciences, you constantly seek knowledge about health and disease in humans. You learn about the workings of the body in sickness and in health, what causes disease, which research methods and techniques there are and which therapies are used, as well as about how you can improve them or develop new ones.

More researchers of big data

  • Thomas Bäck
  • Hendrik Blockeel
  • Jaap Brouwer
  • Jan van Driel
  • Richard Gill
  • Piet Hein van der Graaf
  • Peter Grünwald
  • Jaap van den Herik
  • Jeanine Houwing
  • Ad IJzerman
  • Arno Knobbe
  • Boudewijn Lelieveldt
  • Jacqueline Meulman
  • Barend Mons
  • Siegfried Nijssen
  • Aske Plaat
  • Simon Portegies Zwart
  • Carolien Rieffe
  • Huub Röttgering
  • Eline Slagboom
  • Herman Spaink
  • Arnold Tukker
  • Aad van der Vaart
  • Gilles van Wezel

Thomas Bäck Professor of Natural Computing

Expert in the field of evolutionary algorithms.

Hendrik Blockeel Associate Professor

Developing new data-mining methods to help trace patterns in large amounts of data.

Jaap Brouwer Scientific director, professor of Molecular genetics

Scientific director of Research at the Leiden Institute of Chemistry.

Jan van Driel Professor of Science Education

Director of the Leiden University Graduate School of Teaching (ICLON)

Richard Gill Professor of Mathematical probability

Strong advocate for, among others, the correct use of statistics in trials.

Piet Hein van der Graaf Professor of Systems Pharmacology and director of the Leiden Academic Centre for Drug Research

Developing quick and inexpensive methods for predicting the effect of experimental drugs.

Peter Grünwald Professor of Statistical Learning

Developing reliable probability models.

Jaap van den Herik Professor of Law and Computer Science

Conducts research into data management, data protection, big data and social innovation.

Jeanine Houwing Professor of Medical Statistics

Conducting research into genetic factors that cause hereditary disorders.

Ad IJzerman Professor of Pharmacochemistry

Research centres on the molecular mechanisms of the effect of medications.

Arno Knobbe Postdoc researcher

Prime focus is data mining: using computers to capture knowledge from large amounts of data.

Boudewijn Lelieveldt Professor of Radiology

Seeking ways of analysing and combining the images generated by different imaging techniques.

Jacqueline Meulman Professor of Applied Statistics

Working on new statistical methods for the behavioural sciences and medicine.

Barend Mons Professor of Biosemantics

Working on a brand new method of sharing research data via ‘nanopublications’ that computers can read.

Siegfried Nijssen Lecturer

Conducts research into the application of data mining to bioinformatics and chemoinformatics.

Aske Plaat Scientific director, professor of Data Science

Areas of interest include the development of search algorithms.

Simon Portegies Zwart Professor of Numerical star dynamics

Developing software to facilitate extremely complex and precise calculations in astronomy research.

Carolien Rieffe Professor by Special Appointment of Social and Emotional Development of Children with Auditory or Communication Impairments

Studies the emotional development of children who are deaf and/or have an autism spectrum disorder.

Huub Röttgering Scientific director, professor of Observational cosmology

Research includes the hunt for methods of analysing the gigantic data streams from radio telescopes.

Eline Slagboom Professor of Molecular Epidemiology

Studies ageing processes and their role in the occurrence of common diseases.

Herman Spaink Scientific director, professor of Molecular cell biology

Conducting research into communication between cells, in particular those of different organisms.

Arnold Tukker Scientific director, professor of Industrial Ecology

Specialised in the area of integrated ecology and economic and raw-material databases and models.

Aad van der Vaart Scientific director, professor of Stochastics

Researching how to draw reliable information from large quantities of messy data.

Gilles van Wezel Professor of Molecular Biotechnology

Seeking new antibiotics and ways to improve the production of existing antibiotics.

Impact: influence on the world

The smartest method for deciphering data. It may sound vague, but this science exerts a huge influence on our lives. ‘Consider connectivity via the internet and friendship networks or how intelligent the computers are that take our work out of our hands,’ says Joost Kok. ‘Data science is behind all of this. The same is also true for a recent development such as wireless payment processes. And developments are taking place at a rapid rate, so fast that we will think and act very differently in ten years’ time.’ It is thanks to the work of Joost Kok, who studies the fundamental theory behind this technology, that these changes are possible.

Read more

Joost Kok: “Data science has much influence on connectivity via the internet”.

The world of...

Discover the world in Leiden. Leiden’s researchers collaborate with colleagues throughout the world, often from other adjacent disciplines. Joost Kok also works with eminent colleagues from different countries. The world map below shows a number of Joost Kok’s global contacts (zoom in on the map to see the markers more clearly).