Hong Kong secondary school students’ performance has fallen in an international assessment focused on three core subjects, with their science score dropping out of the global top 10 for the first time in the study’s history.Experts said on Tuesday that the decline in Hong Kong scores in the Programme for International Student Assessment (Pisa) was partly due to the post-Covid impact on study habits and learning motivation.Held every three years, Pisa is a worldwide study by the Organisation for Economic Cooperation and Development (OECD) that tests 15-year-old students on reading, mathematics and science.The latest study, which ranked 91 countries and economies, was conducted from May to July 2025.Each cycle since 2012 has also featured an “innovative domain”, which refers to a rotating test topic that measures real-world skills.