@inproceedings{BarronCedenoAlamStrussetal., author = {Barr{\´o}n-Cede{\~n}o, Alberto and Alam, Firoj and Struß, Julia Maria and Nakov, Preslav and Chakraborty, Tanmoy and Elsayed, Tamer and Przybyła, Piotr and Caselli, Tommaso and Da San Martino, Giovanni and Haouari, Fatima and Hasanain, Maram and Li, Chengkai and Piskorski, Jakub and Ruggeri, Federico and Song, Xingyi and Suwaileh, Reem}, title = {Overview of the CLEF-2024 CheckThat! Lab : Check-Worthiness, Subjectivity, Persuasion, Roles, Authorities, and Adversarial Robustness}, series = {Experimental IR Meets Multilinguality, Multimodality, and Interaction : 15th International Conference of the CLEF Association, CLEF 2024, Grenoble, France, September 9-12, 2024, Proceedings, Part II}, booktitle = {Experimental IR Meets Multilinguality, Multimodality, and Interaction : 15th International Conference of the CLEF Association, CLEF 2024, Grenoble, France, September 9-12, 2024, Proceedings, Part II}, editor = {Goeuriot, Lorraine and Mulhem, Philippe and Qu{\´e}not, Georges and Schwab, Didier and Di Nunzio, Giorgio Maria and Soulier, Laure and Galušc{\´a}kov{\´a}, Petra and Seco de Herrera, Alba Garc{\´i}a and Faggioli, Guglielmo and Ferro, Nicola}, publisher = {Springer Nature}, address = {Berlin}, isbn = {978-3-031-71907-3}, doi = {10.1007/978-3-031-71908-0}, pages = {28 -- 52}, abstract = {We describe the seventh edition of the CheckThat! lab, part of the 2024 Conference and Labs of the Evaluation Forum (CLEF). Previous editions of CheckThat! focused on the main tasks of the information verification pipeline: check-worthiness, identifying previously fact-checked claims, supporting evidence retrieval, and claim verification. In this edition, we introduced some new challenges, offering six tasks in fifteen languages (Arabic, Bulgarian, English, Dutch, French, Georgian, German, Greek, Italian, Polish, Portuguese, Russian, Slovene, Spanish, and code-mixed Hindi-English): Task 1 on estimation of check-worthiness (the only task that has been present in all CheckThat! editions), Task 2 on identification of subjectivity (a follow up of the CheckThat! 2023 edition), Task 3 on identification of the use of persuasion techniques (a follow up of SemEval 2023), Task 4 on detection of hero, villain, and victim from memes (a follow up of CONSTRAINT 2022), Task 5 on rumor verification using evidence from authorities (new task), and Task 6 on robustness of credibility assessment with adversarial examples (new task). These are challenging classification and retrieval problems at the document and at the span level, including multilingual and multimodal settings. This year, CheckThat! was one of the most popular labs at CLEF-2024 in terms of team registrations: 130 teams. More than one-third of them (a total of 46) actually participated.}, subject = {Desinformation}, language = {en} } @inproceedings{AlamStrussChakrabortyetal., author = {Alam, Firoj and Struß, Julia Maria and Chakraborty, Tanmoy and Dietze, Stefan and Hafid, Salim and Korre, Katerina and Muti, Arianna and Nakov, Preslav and Ruggeri, Federico and Schellhammer, Sebastian and Setty, Vinay and Sundriyal, Megha and Todorov, Konstantin and Venktesh, V.}, title = {The CLEF-2025 CheckThat! Lab}, series = {Advances in Information Retrieval : 47th European Conference on Information Retrieval, ECIR 2025, Lucca, Italy, April 6-10, 2025, Proceedings, Part V}, booktitle = {Advances in Information Retrieval : 47th European Conference on Information Retrieval, ECIR 2025, Lucca, Italy, April 6-10, 2025, Proceedings, Part V}, editor = {Hauff, Claudia and Macdonald, Craig and Jannach, Dietmar and Nardini, Franco Maria and Pinelli, Fabio and Silvestri, Fabrizio and Tonellotto, Nicola}, publisher = {Springer International Publishing}, address = {Cham}, isbn = {978-3-031-88720-8}, issn = {0302-9743}, doi = {/10.1007/978-3-031-88720-8_68}, pages = {467 -- 478}, abstract = {The CheckThat! lab aims to advance the development of innovative technologies designed to identify and to counteract online disinformation and manipulation efforts across various languages and platforms. The first five editions of the CheckThat! lab focused on the main tasks of the information verification pipeline: check-worthiness, evidence retrieval and pairing, and verification. Since the 2023 edition, the lab has broadened the focus and addressed new problems on auxiliary tasks supporting research and decision-making during the verification process. In the 2025 edition of the lab, we consider tasks at the core of the verification pipeline again as well as auxiliary tasks: Task 1 is on identification of subjectivity (a follow up of the CheckThat! 2024 edition), Task 2 is on claim normalization, Task 3 addresses fact-checking numerical claims, and Task 4 focuses on scientific web discourse processing. These tasks represent challenging classification and retrieval problems at the document and at the span level, including multilingual settings.}, subject = {Desinformation}, language = {en} } @inproceedings{AlamStrussChakrabortyetal., author = {Alam, Firoj and Struß, Julia Maria and Chakraborty, Tanmoy and Dietze, Stefan and Hafid, Salim and Korre, Katerina and Muti, Arianna and Nakov, Preslav and Ruggeri, Federico and Schellhammer, Sebastian and Setty, Vinay and Sundriyal, Megha and Todorov, Konstantin and Venktesh, V.}, title = {Overview of the CLEF-2025 CheckThat! Lab : Subjectivity, Fact-Checking, Claim Normalization, and Retrieval}, series = {Experimental IR Meets Multilinguality, Multimodality, and Interaction : 16th International Conference of the CLEF Association, CLEF 2025, Madrid, Spain, September 9-12, 2025, Proceedings}, booktitle = {Experimental IR Meets Multilinguality, Multimodality, and Interaction : 16th International Conference of the CLEF Association, CLEF 2025, Madrid, Spain, September 9-12, 2025, Proceedings}, editor = {Carillo-de-Albornoz, Jorge and Seco de Herrera, Alba Garc{\´i}a and Gonzalo, Julio and Plaza, Laura and Mothe, Josiane and Piroi, Florina and Rosso, Paolo and Spina, Damiano and Faggiolo, Guglielmo and Ferro, Nicola}, publisher = {Springer International Publishing}, address = {Cham}, isbn = {978-3-032-04354-2}, issn = {1611-3349}, doi = {10.1007/978-3-032-04354-2_13}, pages = {223}, 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.}, subject = {Desinformation}, language = {en} } @inproceedings{BarronCedenoAlamChakrabortyetal., author = {Barr{\´o}n-Cede{\~n}o, Alberto and Alam, Firoj and Chakraborty, Tanmoy and Elsayed, Tamer and Nakov, Preslav and Przybyła, Piotr and Struß, Julia Maria and Haouari, Fatima and Hasanain, Maram and Ruggeri, Federico and Song, Xingyi and Suwaileh, Reem}, title = {The CLEF-2024 CheckThat! Lab}, series = {Advances in Information Retrieval}, booktitle = {Advances in Information Retrieval}, editor = {Goharian, Nazli and Tonellotto, Nicola and He, Yulan and Lipani, Aldo and McDonald, Graham and Macdonald, Craig and Ounis, Iadh}, publisher = {Springer International Publishing}, address = {Cham}, isbn = {978-3-031-56069-9}, issn = {0302-9743}, doi = {10.1007/978-3-031-56069-9_62}, pages = {449 -- 458}, abstract = {The first five editions of the CheckThat! lab focused on the main tasks of the information verification pipeline: check-worthiness, evidence retrieval and pairing, and verification. Since the 2023 edition, it has been focusing on new problems that can support the research and decision making during the verification process. In this new edition, we focus on new problems and -for the first time- we propose six tasks in fifteen languages (Arabic, Bulgarian, English, Dutch, French, Georgian, German, Greek, Italian, Polish, Portuguese, Russian, Slovene, Spanish, and code-mixed Hindi-English): Task 1 estimation of check-worthiness (the only task that has been present in all CheckThat! editions), Task 2 identification of subjectivity (a follow up of CheckThat! 2023 edition), Task 3 identification of persuasion (a follow up of SemEval 2023), Task 4 detection of hero, villain, and victim from memes (a follow up of CONSTRAINT 2022), Task 5 Rumor Verification using Evidence from Authorities (a first), and Task 6 robustness of credibility assessment with adversarial examples (a first). These tasks represent challenging classification and retrieval problems at the document and at the span level, including multilingual and multimodal settings.}, subject = {Desinformation}, language = {en} }