Overview of the CLEF-2025 CheckThat! Lab: Subjectivity, Fact-Checking, Claim Normalization, and Retrieval
Alam, Firoj Struß, Julia Maria Chakraborty, Tanmoy Dietze, Stefan Hafid, Salim Korre, Katerina Muti, Arianna Nakov, Preslav Ruggeri, Federico Schellhammer, Sebastian
Alam, Firoj
Struß, Julia Maria
Chakraborty, Tanmoy
Dietze, Stefan
Hafid, Salim
Korre, Katerina
Muti, Arianna
Nakov, Preslav
Ruggeri, Federico
Schellhammer, Sebastian
Supervisor
Department
Natural Language Processing
Embargo End Date
Type
Conference proceeding
Date
2025
License
Language
English
Collections
Research Projects
Organizational Units
Journal Issue
Abstract
This paper presents the eighth edition of the CheckThat! lab, part of the 2025 Conference and Labs of the Evaluation Forum (CLEF). As in previous editions of CheckThat!, the lab offers tasks from the core of the verification pipeline, including check-worthiness, identifying previously fact-checked claims, supporting evidence retrieval, and claim verification as well as auxiliary tasks addressing different facets of individual steps of the pipeline: Task 1 is on identification of subjectivity (a follow-up of the CheckThat! 2024 edition), which is related to the check-worthiness task, Task 2 is on claim normalization, Task 3 addresses fact-checking numerical claims, and Task 4 focuses on scientific web discourse processing. These challenging classification and retrieval problems are offered in different mono-, multi- and crosslingual settings covering more than 20 languages. This year, CheckThat! was one of the most popular labs at CLEF-2025 in terms of team registrations: 177 teams registered, almost half of them actually participating (a total of 83 teams) and 54 submitted system description papers.
Citation
F. Alam et al., “Overview of the CLEF-2025 CheckThat! Lab: Subjectivity, Fact-Checking, Claim Normalization, and Retrieval,” LNCS, vol. 16089, pp. 199–223, 2026, doi: 10.1007/978-3-032-04354-2_13
Source
Lecture Notes in Computer Science
Conference
Experimental IR Meets Multilinguality, Multimodality, and Interaction (CLEF 2025)
Keywords
Fact-Checking, Check-Worthiness, Subjectivity, Claim Verification
Subjects
Source
Experimental IR Meets Multilinguality, Multimodality, and Interaction (CLEF 2025)
Publisher
Springer Nature