TAGCOS: Task-agnostic Gradient Clustered Coreset Selection for Instruction Tuning Data
Jipeng Zhang, Yaxuan Qin, Renjie Pi, Weizhong Zhang, Rui Pan, Tong Zhang
TL;DR
TAGCOS tackles the data-efficiency challenge in instruction tuning by using per-sample gradient features as task-agnostic data representations, then applying gradient-based clustering to handle dataset diversity and a greedy optimal matching pursuit (OMP) strategy to select a compact, informative coreset. Theoretical analysis shows that this gradient-clustering decomposition preserves submodularity properties, enabling efficient optimization and yielding smaller coresets that approximate full-gradient objectives. Empirically, TAGCOS achieves near full-dataset performance with only 5% of the data across multiple benchmarks and transfers effectively between models, offering practical scalability for large language models. Overall, the approach provides a principled, scalable pipeline for data-efficient instruction tuning with strong empirical and theoretical support.
Abstract
Instruction tuning has achieved unprecedented success in NLP, turning large language models into versatile chatbots. However, the increasing variety and volume of instruction datasets demand significant computational resources. To address this, it is essential to extract a small and highly informative subset (i.e., Coreset) that achieves comparable performance to the full dataset. Achieving this goal poses non-trivial challenges: 1) data selection requires accurate data representations that reflect the training samples' quality, 2) considering the diverse nature of instruction datasets, and 3) ensuring the efficiency of the coreset selection algorithm for large models. To address these challenges, we propose Task-Agnostic Gradient Clustered COreset Selection (TAGCOS). Specifically, we leverage sample gradients as the data representations, perform clustering to group similar data, and apply an efficient greedy algorithm for coreset selection. Experimental results show that our algorithm, selecting only 5% of the data, surpasses other unsupervised methods and achieves performance close to that of the full dataset.
