We describe the third edition of the CheckThat! Lab, which is part of the 2020 Cross-Language Evaluation Forum (CLEF). CheckThat! proposes four complementary tasks and a related task from previous lab editions, offered in English, Arabic, and Spanish. Task 1 asks to predict which tweets in a Twitter stream are worth fact-checking. Task 2 asks to determine whether a claim posted in a tweet can be verified using a set of previously fact-checked claims. Task 3 asks to retrieve text snippets from a given set of Web pages that would be useful for verifying a target tweet's claim. Task 4 asks to predict the veracity of a target tweet's claim using a set of Web pages and potentially useful snippets in them. Finally, the lab offers a fifth task that asks to predict the check-worthiness of the claims made in English political debates and speeches. CheckThat! features a full evaluation framework. The evaluation is carried out using mean average precision or precision at rank k for ranking tasks, and F1 for classification tasks.

该研究介绍了第三版的 CheckThat! 实验室，该实验室是 2020 年跨语言评估论坛（CLEF）的一部分，并在英语，阿拉伯语和西班牙语中提供四个任务，还提供了与先前实验室版本相关的任务。CheckThat!实验室提供完整的评估框架，使用平均精度（MAP）或rank k 准确率来评估排名任务，并使用 F1 来评估分类任务。

CLEF 2020 中的 CheckThat!：在社交媒体中实现自动认证和验证声索