In long structured document retrieval, existing methods typically fine-tune pre-trained language models (PLMs) using contrastive learning on datasets lacking explicit structural information. This practice suffers from two critical issues: 1) current methods fail to leverage structural features and element-level semantics effectively, and 2) the lack of datasets containing structural metadata. To bridge these gaps, we propose SEAL, a novel contrastive learning framework. It leverages structure-aware learning to preserve semantic hierarchies and masked element alignment for fine-grained semantic discrimination. Furthermore, we release StructDocRetrieval, a long structured document retrieval dataset with rich structural annotations. Extensive experiments on both the released and industrial datasets across various modern PLMs, and online A/B testing demonstrate consistent improvements, boosting NDCG@10 from 73.96% to 77.84% on BGE-M3. The resources are available at https://github.com/xinhaoH/SEAL.

“Recent years have seen a lot of efforts in attacking the issue of language priors in the field ofVisual Question Answering (VQA). Among the extensive efforts, causal inference is regarded asa promising direction to mitigate language bias by weakening the direct causal effect of questionson answers. In this paper, we follow the same direction and attack the issue of language priorsby incorporating counterfactual data. Moreover, we propose a two-stage training strategy whichis deemed to make better use of counterfactual data. Experiments on the widely used bench-mark VQA-CP v2 demonstrate the effectiveness of the proposed approach, which improves thebaseline by 21.21% and outperforms most of the previous systems.”