  We describe SemEval-2021 task 6 on Detection of Persuasion Techniques in
Texts and Images: the data, the annotation guidelines, the evaluation setup,
the results, and the participating systems. The task focused on memes and had
three subtasks: (i) detecting the techniques in the text, (ii) detecting the
text spans where the techniques are used, and (iii) detecting techniques in the
entire meme, i.e., both in the text and in the image. It was a popular task,
attracting 71 registrations, and 22 teams that eventually made an official
submission on the test set. The evaluation results for the third subtask
confirmed the importance of both modalities, the text and the image. Moreover,
some teams reported benefits when not just combining the two modalities, e.g.,
by using early or late fusion, but rather modeling the interaction between them
in a joint model.
