  Contrastive-learning-based methods have dominated sentence representation
learning. These methods regularize the representation space by pulling similar
sentence representations closer and pushing away the dissimilar ones and have
been proven effective in various NLP tasks, e.g., semantic textual similarity
(STS) tasks. However, it is challenging for these methods to learn fine-grained
semantics as they only learn from the inter-sentence perspective, i.e., their
supervision signal comes from the relationship between data samples. In this
work, we propose a novel denoising objective that inherits from another
perspective, i.e., the intra-sentence perspective. By introducing both discrete
and continuous noise, we generate noisy sentences and then train our model to
restore them to their original form. Our empirical evaluations demonstrate that
this approach delivers competitive results on both semantic textual similarity
(STS) and a wide range of transfer tasks, standing up well in comparison to
contrastive-learning-based methods. Notably, the proposed intra-sentence
denoising objective complements existing inter-sentence contrastive
methodologies and can be integrated with them to further enhance performance.
Our code is available at https://github.com/xinghaow99/DenoSent.
