Contrastive learning has become a new paradigm for unsupervised sentence
embeddings. Previous studies focus on instance-wise contrastive learning,
attempting to construct positive pairs with textual data augmentation. In this
paper, we propose a novel Contrastive learning method with Prompt-derived
Virtual semantic Prototypes (ConPVP). Specifically, with the help of prompts,
we construct virtual semantic prototypes to each instance, and derive negative
prototypes by using the negative form of the prompts. Using a prototypical
contrastive loss, we enforce the anchor sentence embedding to be close to its
corresponding semantic prototypes, and far apart from the negative prototypes
as well as the prototypes of other sentences. Extensive experimental results on
semantic textual similarity, transfer, and clustering tasks demonstrate the
effectiveness of our proposed model compared to strong baselines. Code is
available at this https URL.

本文提出了一种新的对比学习方法，使用提示词构建每个实例的虚拟语义原型，并通过负面提示形式派生负面原型，通过原型对比损失，将锚定的句子嵌入与其对应的语义原型相近，并与负面原型及其他句子的原型相距较远。实验结果表明，与强基线模型相比，我们提出的方法在语义文本相似性、转移和聚类任务上效果显著。