We invite you to participate in the 2023 edition of the CheckThat! Lab at CLEF 2023. This year, we feature five tasks ---one follow-up and four new--- that correspond to important components within and around the full fact-checking pipeline in multiple languages:

Task 1 Check-worthiness in tweets: This is the sixth round of the check-worthiness task. It allows us to reduce the workload of listening to social media for tweets and claims that would require the attention of a journalist. We offer two task modalities.. Subtask 1A: Multimodal tweets including text and picture (for the first time!). Available in Arabic and English. Subtask 1B: Unimodal tweets and claims. Available in Arabic, English and Spanish. Subtask 1C: US political debates, text only. Available in English

Task 2 Subjectivity in news articles: Distinguish whether a sentence from a news article expresses the subjective view of the author behind it or presents an objective view on the covered topic instead. Available in Arabic, Dutch, English, Italian, German, and Turkish.

Task 3 Political bias of news articles and news media. Detect political bias of news reporting at the article and at the media level. It includes two subtasks: Subtask 3A: Given an article, classify its political leaning as left, center or right. Subtask 3B: Given the URL to a news outlet (e.g., www.cnn.com), predict the overall political bias of that news outlet as left, center or right leaning. Available in English.

Task 4 Factuality of reporting of news media. Identify the factuality of reporting at the media level. Given the URL to a news outlet the task asks to predict the factuality of reporting of that news outlet: low, mixed, and high. Available in English.

Task 5 Authority finding on twitter. Given a tweet stating a rumor, a model has to retrieve a ranked list of authority Twitter accounts that can help verify the rumor; i.e. they may tweet evidence that supports or denies the rumor. Available in Arabic.

Further information: https://checkthat.gitlab.io/ Datasets: https://gitlab.com/checkthat_lab/clef2023-checkthat-lab Register and participate: https://clef2023-labs-registration.dei.unipd.it/registrationForm.php

Important Dates --------------------- November 2022: Lab registration opens December 2022: Release of the training materials April 2023: Lab registration closes May 2023: Beginning of the evaluation cycle May 2023: End of the evaluation cycle (run submission) May 2023: Deadline for the submission of working notes June 2023: Notification of acceptance of working notes July 2023: Deadline for submission of camera-ready working notes July 2023: Preview of working notes 18-21 September: CLEF 2023 Conference in Thessaloniki, Greece

Best The CLEF-2023 CheckThat! Lab Shared Task Organizers