State-of-the-art models can perform well in controlled environments, but they often struggle when presented with out-of-distribution (OOD) examples, making OOD detection a critical component of NLP systems. In this paper, we focus on highlighting the limitations of existing approaches to OOD detection in NLP. Specifically, we evaluated eight OOD detection methods that are easily integrable into existing NLP systems and require no additional OOD data or model modifications. One of our contributions is providing a well-structured research environment that allows for full reproducibility of the results. Additionally, our analysis shows that existing OOD detection methods for NLP tasks are not yet sufficiently sensitive to capture all samples characterized by various types of distributional shifts. Particularly challenging testing scenarios arise in cases of background shift and randomly shuffled word order within in domain texts. This highlights the need for future work to develop more effective OOD detection approaches for the NLP problems, and our work provides a well-defined foundation for further research in this area.

本文着重介绍了现有方法在处理NLP中OOD检测时的局限性, 对八种常见的OOD检测方法进行了评估并分析了其存在的问题，发现现有方法对于各类型分布偏移的检测敏感性不够，在领域内文本中存在令人困惑的测试场景，而需要开发更有效的OOD检测方法，本文为未来的研究提供了一个良好的、定义明确的基础。

文本分类任务中传统的外部分布检测方法的基准测试