Title: TARE: Lightweight Token-Aware Representation Editing for Fine-tuning Transformer
Primary area: unsupervised, self-supervised, semi-supervised, and supervised representation learning
Keywords: Representation Editing, Fine-tuning, Transformer

Abstract: Parameter-efficient fine-tuning (PEFT) of large Transformers often struggles to balance effectiveness with efficiency. Methods based on low-rank adaptation can be resource-intensive, while representation-editing techniques that apply a single, global transformation tend to underfit fine-grained, token-level contexts. The core challenge is achieving token-aware, fine-grained edits while keeping inference overhead and the hyperparameter tuning burden negligible. Our work introduce Token-Aware Representation Editing (TARE), a novel PEFT method. After each feed-forward network (FFN) block, TARE employs a lightweight selector that scores a small pool of "editors" for each token's hidden representation. It sparsely activates only the top-scoring editors and mixes their element-wise edits to update the representation. Because the edits are computationally minimal diagonal operations and are sparsely activated, TARE adds near-zero inference overhead and introduces no rank or scaling hyperparameters. Our work conduct extensive experiments on LLaMA-3-8B across eight knowledge reasoning and seven mathematical reasoning tasks, and on RoBERTa-base/large for the GLUE benchmark. Compared to strong baselines like LoRA, DoRA, MiLoRA, LoReFT, and RED, TARE achieves state-of-the-art results. It attains an 86.7% average on knowledge reasoning tasks, 76.7% on mathematical reasoning tasks, and 88.3% on the GLUE benchmark. These results are achieved while tuning only 0.0392% of the model's parameters and using approximately 20 GiB of memory, surpassing prior methods by several percentage points and demonstrating exceptional resource efficiency. An anonymized implementation is available at: https://anonymous.4open.science/r/tare-BCF5/.

TL;DR: Lightweight Token-Aware Representation Editing for Fine-tuning Transformer