Large language models (LLMs)  have advanced in large strides due to the effectiveness of the self-attention mechanism that processes and compares all tokens at once.
However, this mechanism comes with a fundamental issue — the predetermined context window is bound to be limited. Despite attempts to extend the context window through methods like extrapolating the positional embedding, using recurrence, or selectively retrieving essential parts of the long sequence, long-text understanding continues to be a challenge.
We propose an alternative approach which instead treats the LLM as an interactive agent, allowing it to decidehowto read the text via iterative prompting.
We introduceMemWalker, a method that first processes the long context into a tree of summary nodes. Upon receiving a query, the model navigates this tree in search of relevant information, and responds once it gathers sufficient information. On long-text question answering tasks
our method outperforms baseline approaches that use long context windows, recurrence, and retrieval. We show that, beyond effective reading,MemWalkerenhances explainability by highlighting the reasoning steps as it interactively reads the text; pinpointing the relevant text segments related to the query.