  Large language models (LLMs) are initially pretrained for broad capabilities
and then finetuned with instruction-following datasets to improve their
performance in interacting with humans. Despite advances in finetuning, a
standardized guideline for selecting high-quality datasets to optimize this
process remains elusive. In this paper, we first propose InstructMining, an
innovative method designed for automatically selecting premium
instruction-following data for finetuning LLMs. Specifically, InstructMining
utilizes natural language indicators as a measure of data quality, applying
them to evaluate unseen datasets. During experimentation, we discover that
double descent phenomenon exists in large language model finetuning. Based on
this observation, we further leverage BlendSearch to help find the best subset
among the entire dataset (i.e., 2,532 out of 100,000). Experiment results show
that InstructMining-7B achieves state-of-the-art performance on two of the most
popular benchmarks: LLM-as-a-judge and Huggingface OpenLLM leaderboard.
