Generalization or Memorization: Dynamic Decoding for Mode Steering
Authors: name: Xuanming Zhang
Published: 2025-10-25 00:50:47

Abstract: Large Language Models (LLMs) exhibit a troubling duality, capable of both
remarkable generalization and brittle, verbatim memorization of their training
data. This unpredictability undermines their reliability in high-stakes
applications. In this work, we propose a unified framework to understand,
identify, and control these distinct reasoning modes. First, we introduce a
theoretical model based on the Information Bottleneck (IB) principle,
formalizing generalization as the learning of a compressed, task-relevant
representation and memorization as a failure to compress. Building on this
theory, we develop Dynamic Mode Steering (DMS), a novel inference-time
algorithm which comprises two components: (1) a lightweight, causally-grounded
linear probe that identifies the model's instantaneous reliance on
memorization, and (2) a dynamic activation steering mechanism that nudges the
model's computation towards pre-identified generalization circuits. We frame
DMS as a form of adaptive, self-contrastive decoding. Experiments on reasoning
and faithfulness tasks demonstrate that DMS significantly improves logical
consistency and factual accuracy, thereby offering a principled approach to
enhancing LLM reliability.