The "lost-in-the-middle" problem in LLMs refers to the difficulty faced by these models in identifying and using relevant information situated in the middle of a long input context3. Despite being able to handle large input contexts, LLMs tend to focus on information at the beginning and end, often neglecting the critical information in between, leading to reduced accuracy in tasks requiring access to information spread throughout the entire text.
The "found-in-the-middle" mechanism is a novel calibration method proposed by researchers from the University of Washington, MIT, Google Cloud AI Research, and Google to address the "lost-in-the-middle" problem in large language models (LLMs). This mechanism disentangles positional bias from attention scores, enabling LLMs to attend to contexts based on their relevance rather than their position, and significantly improves performance in long-context utilization tasks6.
Current methods to tackle the lost-in-the-middle issue often involve re-ranking the relevance of documents and repositioning the most pertinent ones at the beginning or end of the input sequence3. However, these methods usually require additional supervision or fine-tuning and do not fundamentally address the LLMs' ability to utilize mid-sequence information effectively3.