FPAI at SemEval-2021 Task 6: BERT-MRC for Propaganda Techniques Detection

Xiaolong Hou, Junsong Ren, Gang Rao, Lianxin Lian, Zhihao Ruan, Yang Mo, JIanping Shen


Abstract
The objective of subtask 2 of SemEval-2021 Task 6 is to identify techniques used together with the span(s) of text covered by each technique. This paper describes the system and model we developed for the task. We first propose a pipeline system to identify spans, then to classify the technique in the input sequence. But it severely suffers from handling the overlapping in nested span. Then we propose to formulize the task as a question answering task by MRC framework which achieves a better result compared to the pipeline method. Moreover, data augmentation and loss design techniques are also explored to alleviate the problem of data sparse and imbalance. Finally, we attain the 3rd place in the final evaluation phase.
Anthology ID:
2021.semeval-1.146
Volume:
Proceedings of the 15th International Workshop on Semantic Evaluation (SemEval-2021)
Month:
August
Year:
2021
Address:
Online
Venues:
ACL | IJCNLP | SemEval
SIG:
SIGLEX
Publisher:
Association for Computational Linguistics
Note:
Pages:
1056–1060
Language:
URL:
https://aclanthology.org/2021.semeval-1.146
DOI:
10.18653/v1/2021.semeval-1.146
Bibkey:
Copy Citation:
PDF:
https://aclanthology.org/2021.semeval-1.146.pdf