GNN-encoder: Learning a Dual-encoder Architecture via Graph Neural Networks for Dense Passage Retrieval

Understand

Recently, retrieval models based on dense representations are dominant in passage retrieval tasks, due to their outstanding ability in terms of capturing semantics of input text compared to the traditional sparse vector space models.

• A common practice of dense retrieval models is to exploit a dual-encoder architecture to represent a query and a passage independently.
• Though efficient, such a structure loses interaction between the query-passage pair, resulting in inferior accuracy.
• To enhance the performance of dense retrieval models without loss of efficiency, we propose a GNN-encoder model in which query (passage) information is fused into passage (query) representations via graph neural networks that are constructed by queries and their top retrieved passages.