The facts and time in the document are intricately intertwined, making
temporal reasoning over documents challenging. Previous work models time
implicitly, making it difficult to handle such complex relationships. To
address this issue, we propose MTGER, a novel Multi-view Temporal Graph
Enhanced Temporal Reasoning framework for temporal reasoning over time-involved
documents. Concretely, MTGER explicitly models the temporal relationships among
facts by multi-view temporal graphs. On the one hand, the heterogeneous
temporal graphs explicitly model the temporal and discourse relationships among
facts; on the other hand, the multi-view mechanism captures both time-focused
and fact-focused information, allowing the two views to complement each other
through adaptive fusion. To further improve the implicit reasoning capability
of the model, we design a self-supervised time-comparing objective. Extensive
experimental results demonstrate the effectiveness of our method on the TimeQA
and SituatedQA datasets. Furthermore, MTGER gives more consistent answers under
question perturbations.

我们提出了 MTGER，这是一个新颖的多视图时序图增强时间推理框架，用于对涉及时间的文档进行时间推理。通过多视图时序图，MTGER 显式地建模了事实之间的时间关系，实现了时间和论述关系的显式建模，并采用自适应融合机制捕捉两个视图之间的时间和事实信息。通过自监督时间比较目标，进一步提高了模型的隐式推理能力。实验结果表明我们的方法在 TimeQA 和 SituatedQA 数据集上的有效性，并且在问题干扰下给出了更一致的答案。