Noisy Self-Training with Synthetic Queries for Dense Retrieval
Fan Jiang Tom Drummond Trevor Cohn
Although existing neural retrieval models reveal promising results when
training data is abundant and the performance keeps improving as training data
increases, collecting high-quality annotated data is prohibitively costly. To
this end, we introduce a novel noisy self-training framework combined with
synthetic queries, showing that neural retrievers can be improved in a
self-evolution manner with no reliance on any external models. Experimental
results show that our method improves consistently over existing methods on
both general-domain (e.g., MS-MARCO) and out-of-domain (i.e., BEIR) retrieval
benchmarks. Extra analysis on low-resource settings reveals that our method is
data efficient and outperforms competitive baselines, with as little as 30% of
labelled training data. Further extending the framework for reranker training
demonstrates that the proposed method is general and yields additional gains on
tasks of diverse domains.\footnote{Source code is available at
\url{https://github.com/Fantabulous-J/Self-Training-DPR}}