Stats and the human touch: Professor Li shares insights at World Statistics Day

Professor Li Wai-keung, Dean of FLASS, was invited to give a speech at the fourth World Statistics Day on 20 October. His talk, titled “Can Data Speak for Itself? Basic statistical principles that are still valid in the era of big data”, explored common statistical fallacies, including biases in sample selection and the pitfalls of spurious correlations. At a time when many believe AI can replace humans in every domain, he reminded the audience that data does not speak for itself, as it is people who give numbers context and meaning.

“The claim that numbers can speak for themselves overlooks the complexity of data interpretation. Statistics offers many powerful tools to analyse data, known as variables when attempting to establish relationships among them. However, a strong correlation or association between two variables does not always imply that changes in one cause changes in the other. Often, the relationship is driven by other lurking, unknown variables,” said Professor Li, a veteran statistician renowned for his work in time series analysis.

He further explained that while statistical inference can establish correlations, scientific methods and theories are required to determine whether genuine causal relationships exist. “Such theories not only predict that one thing leads to another, but also explain the connections between variables. To prove real causation, we need to conduct a series of carefully controlled randomised experiments,” he added.

World Statistics Day was first celebrated on 20 October 2010 to raise awareness of the achievements of official statistics and the importance of reliable, timely data for informed policymaking. Since then, it has been observed every five years on 20 October. The fourth World Statistics Day, commemorated on 20 October 2025 under the theme “Driving change with quality statistics and data for everyone”, highlights the growing importance of high-quality statistics in a rapidly changing world, supporting informed research, planning and decision-making across sectors.

The Census and Statistics Department (C&SD) jointly organised a public lecture on “Quality Statistics and Data for Everyone” on 20 October 2025 with EdUHK, the Hong Kong Statistical Society (HKSS) and the Education Bureau, in celebration of the occasion as proclaimed by the United Nations Statistics Division. Mr Leo Yu, Commissioner for Census and Statistics, and Professor Chan Ngai-hang, President of HKSS, officiated the event. EdUHK President Professor John Lee Chi-Kin also gave a pre-recorded opening message at the event.

In addition to Professor Li, Ms Polly Wong, former Marketing Science Partner of Meta Hong Kong, and Mr Michael Choi of C&SD also delivered lectures. Drawing on her extensive commercial experience, Ms Wong discussed how AI and statistics can support data-driven business decisions. Mr Choi, a statistician (Census Planning) from C&SD, spoke about the upcoming 2026 Population Census and the innovative measures being introduced, highlighting how AI is being used to enhance the efficiency of data collection and analysis.

Professor Philip Yu Leung-ho from the Department of Mathematics and Information Technology, and Associate Director of the University Research Facility of Data Science and Artificial Intelligence, introduced the speakers and moderated the Q&A. The event, held at EdUHK’s Tseung Kwan O Study Centre, received favourable responses from primary and secondary school teachers, students, government officials and members of the public.