FPAI at SemEval-2021 Task 6: BERT-MRC for Propaganda Techniques Detection
Xiaolong Hou, Ren Junsong, G. Sasibushana Rao, Lianxin Lian, Zhihao Ruan, Yang Mo, Jianping Shen · 2021
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 machine reading comprehension (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 sparsity and imbalance.Finally, we attain the 3 rd place in the final evaluation phase.