Bi-Encoder

• DPR (Dense Passage Retrieval)

  Dual BERT encoder model that retrieves passages by embedding queries and documents into a shared dense vector space; foundational bi-encoder for open-domain QA.

• Knowledge Distillation for IR

  Training a fast bi-encoder (student) to mimic the ranking scores of a slow cross-encoder (teacher); the dominant approach for improving dense retrieval without cross-encoder latency.

• Bi-Encoder

  Neural architecture encoding query and document independently into separate embeddings, enabling fast retrieval via approximate nearest-neighbour search.