Proceedings of the 5th International Workshop on Learning to Quantify (LQ 2025)

The 5th International Workshop on Learning to Quantify (LQ 2025 – https: //lq-2025.github.io/) has been held in Porto, PT, on September 15, 2025, as a satellite workshop of the European Conference on Machine Learning and Principles and Practice of Knowledge Discovery in Databases (ECML/PKDD 2025). While the 1st edition of the workshop (LQ 2021 – https://cikmlq2021. github.io/) had to be an entirely online event due to the COVID-19 pan- demic, the 2nd edition (LQ 2022 – https://lq-2022.github.io/), 3rd edition (LQ 2023 – https://lq-2023.github.io/), 4th edition (LQ 2024 – https://lq-2024.github.io/), and this 5th edition, have been hybrid events, with presentations given in-presence, and both in-presence attendees and remote attendees. The LQ 2025 workshop consisted of the presentations of seven contributed papers, that had each gone through a rigorous peer-reviewing process by three reviewers each, and a final collective discussion on the open problems of learning to quantify and on future initiatives. The present volume con- tains the text of five of the seven presentations given at the workshop (for the other two presentations the authors asked for their papers not to be in the proceedings). We hope that the availability of the present volume will increase the interest in the subject of quantification on the part of researchers and practitioners alike, and will contribute to making quantification better known to potential users of this technology and to researchers interested in advancing the field.