Exploiting Memorization: Understanding the CLM Objective for Knowledge Encoding in LLMs

Table of Links

Abstract and 1. Introduction

2. Background

3. Method

4. Experiments

   4.1 Multi-hop Reasoning Performance

   4.2 Reasoning with Distractors

   4.3 Generalization to Real-World knowledge

   4.4 Run-time Analysis

   4.5 Memorizing Knowledge

5. Related Work

6. Conclusion, Acknowledgements, and References

A. Dataset

B. In-context Reasoning with Distractors

C. Implementation Details

D. Adaptive Learning Rate

E. Experiments with Large Language Models

2 Background

Notation We use f : X × θ → Y to refer to parameterised functions in which X is the set of possible inputs and θ are their possible weights (parameters). We use fθ : x 7→ f(x, θ) to easily refer to any f with a given set of parameters θ. We describe reasoning problems using tuples (K, x, y∗ , Y ) such that y ∈ Y is the correct answer for the question x given facts K, and use D to refer to sets of such problems. When it is clear from context, we drop Y and use only (K, x, y∗ ).

Language Modeling and Memorization In the causal language modeling (CLM) objective, a parameterized model fθ is trained to estimate the conditional probabilities of each token in a sequence given its predecessors: p(xt|x) Specifically, we train fθ to approximate p using the CLM loss:

This training objective allows language models to memorize individual training examples [10, 11], and we will exploit this ability to memorize and draw on contextual knowledge in our work.