Overview of the CLEF-2025 CheckThat! Lab: Subjectivity, Fact-Checking, Claim Normalization, and Retrieval

  • Firoj Alam*
  • , Julia Maria Struß
  • , Tanmoy Chakraborty
  • , Stefan Dietze
  • , Salim Hafid
  • , Katerina Korre
  • , Arianna Muti
  • , Preslav Nakov
  • , Federico Ruggeri
  • , Sebastian Schellhammer
  • , Vinay Setty
  • , Megha Sundriyal
  • , Konstantin Todorov
  • , V. Venktesh
  • *Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

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.

Original languageEnglish
Title of host publicationExperimental Ir Meets Multilinguality, Multimodality, And Interaction, Clef 2025
EditorsJ Carrillo-De-Albornoz, AGS DeHerrera, J Gonzalo, L Plaza, J Mothe, F Piroi, P Rosso, D Spina, G Faggioli, N Ferro
PublisherSpringer Science and Business Media Deutschland GmbH
Pages199-223
Number of pages25
Volume16089
ISBN (Electronic)978-3-032-04354-2
ISBN (Print)9783032043535
DOIs
Publication statusPublished - 2026
Event16th International Conference of the Cross-Language Evaluation Forum for European Languages, CLEF 2025 - Madrid, Spain
Duration: 9 Sept 202512 Sept 2025

Publication series

NameLecture Notes In Computer Science

Conference

Conference16th International Conference of the Cross-Language Evaluation Forum for European Languages, CLEF 2025
Country/TerritorySpain
CityMadrid
Period9/09/2512/09/25

Keywords

  • Check-Worthiness
  • Claim verification
  • Fact-Checking
  • Subjectivity

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