Lost in the Middle: How Language Models Use Long Contexts

Liu et al., 2024, Lost in the Middle (Transactions of ACL, vol. 12)

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2 cards in “5 Is More Context Always Better? A Case Study With Open-Domain QA” · whole deck

5 Is More Context Always Better? A Case Study With Open-Domain QA

  1. What did the open-domain QA case study show about adding retrieved documents?
    Reader accuracy saturated long before retriever recall did: going from 20 to 50 retrieved documents gained only about 1–1.5 points while greatly increasing context length, latency and cost.
  2. What practical remedies for retrieval-augmented generation do Liu et al. suggest?
    Rerank retrieved documents so relevant ones come near the start of the context, and truncate the ranked list, retrieving fewer documents when appropriate.

Source

  • Nelson F. Liu, Kevin Lin, John Hewitt, Ashwin Paranjape, Michele Bevilacqua, Fabio Petroni and Percy Liang. 2024. Lost in the Middle: How Language Models Use Long Contexts. In Transactions of the Association for Computational Linguistics, vol. 12, pp. 157–173. License: CC BY 4.0. Flashcards adapted from this work. doi:10.1162/tacl_a_00638 https://aclanthology.org/2024.tacl-1.9/