The Landscape of Memorization in LLMs: Mechanisms, Measurement, and Mitigation
It addresses privacy and ethical concerns for AI developers and researchers, but is incremental as it reviews existing work without introducing new methods or results.
This paper synthesizes studies on memorization in Large Language Models (LLMs), exploring its mechanisms, measurement methods like prefix-based extraction, and mitigation strategies such as differential privacy, while identifying open challenges in balancing privacy and utility.
Large Language Models (LLMs) have demonstrated remarkable capabilities across a wide range of tasks, yet they also exhibit memorization of their training data. This phenomenon raises critical questions about model behavior, privacy risks, and the boundary between learning and memorization. Addressing these concerns, this paper synthesizes recent studies and investigates the landscape of memorization, the factors influencing it, and methods for its detection and mitigation. We explore key drivers, including training data duplication, training dynamics, and fine-tuning procedures that influence data memorization. In addition, we examine methodologies such as prefix-based extraction, membership inference, and adversarial prompting, assessing their effectiveness in detecting and measuring memorized content. Beyond technical analysis, we also explore the broader implications of memorization, including the legal and ethical implications. Finally, we discuss mitigation strategies, including data cleaning, differential privacy, and post-training unlearning, while highlighting open challenges in balancing the minimization of harmful memorization with utility. This paper provides a comprehensive overview of the current state of research on LLM memorization across technical, privacy, and performance dimensions, identifying critical directions for future work.