Sharing knowledge between information extraction tasks has always been a challenge due to the diverse data formats and task variations. Meanwhile, this divergence leads to information waste and increases difficulties in building complex applications in real scenarios. Recent studies often formulate IE tasks as a triplet extraction problem. However, such a paradigm does not support multi-span and n-ary extraction, leading to weak versatility. To this end, we reorganize IE problems into unified multi-slot tuples and propose a universal framework for various IE tasks, namely Mirror. Specifically, we recast existing IE tasks as a multi-span cyclic graph extraction problem and devise a non-autoregressive graph decoding algorithm to extract all spans in a single step. It is worth noting that this graph structure is incredibly versatile, and it supports not only complex IE tasks, but also machine reading comprehension and classification tasks. We manually construct a corpus containing 57 datasets for model pretraining, and conduct experiments on 30 datasets across 8 downstream tasks. The experimental results demonstrate that our model has decent compatibility and outperforms or reaches competitive performance with SOTA systems under few-shot and zero-shot settings. The code, model weights, and pretraining corpus are available at https://github.com/Spico197/Mirror .

“多标签文本分类((Multi-Label Text Classification, MLTC)旨在从预定义的候选标签集合中选择一个或多个文本对应的类别,是自然语言处理C)旨在从预定义的候选标签集合中选择一个或多个文本对应的类别,是自然语言处理(Natural Language Processing,NLP)的一项基本任务。前人工作大多基于规范且全面的标注数据集,而这些规范数据集需要严格的质量控制,一般很难获取。在真实的标注过程中,难免会丢失掉一些相关标签,进而导致不完全标注问题。为此本文提出了一种基于局部标注的自监督框架(Partial Self-Training,PST),该框架利用教师模型自动地给大规模无标注数据打伪标签,同时给不完全标注数据补充缺失标签,最后再利用这些数据反向更新教师模型。在合成数据集和真实数据集上的实验表明,本文提出的PST框架兼容现有的各类多标签文本分类模型,并且可以缓解不完全标注数据对模型的影响。”