AIExplainer
Large Language Models Intermediate 1 min read

What is a lost-in-the-middle effect?

An LLM's tendency to use information from the start and end of a long context window more effectively than information from the middle.

An LLM's tendency to use information from the start and end of a long context window more effectively than information from the middle. That is, given a long context, the lost-in-the-middle effect causes accuracy to be: - Relatively high when the relevant information to form a response is near the beginning or end of the context. - Relatively low when the relevant information to form a response is in the middle of the context. The term comes from Lost in the Middle: How Language Models Use Long Contexts.

Practitioners refer to lost-in-the-middle effect when building, training, or evaluating machine learning systems. It appears in research papers, product documentation, and technical discussions about AI capabilities and limitations.