🤖 AI Summary
In instruction tuning of small language models, existing synthetic data selection methods suffer from inefficiency and overreliance on single quality signals (e.g., reward scores or perplexity), leading to insufficient domain coverage and response diversity.
Method: We propose CrowdSelect—a diversity-aware data selection framework that jointly leverages multi-LLM consensus and reward model evaluation. It introduces three foundational metrics—semantic coverage, logical rigor, and expressive diversity—based on cross-model response consistency, integrated via hierarchical clustering to jointly optimize both quality and diversity. The method supports feature modeling of instruction-response pairs and is compatible with both full-parameter and LoRA fine-tuning.
Results: CrowdSelect achieves state-of-the-art performance on MT-Bench and Arena-Hard, improving fine-tuned Llama-3.2-3B-Instruct by +11.1% and +4.81%, respectively, outperforming all prior approaches.
📝 Abstract
Distilling advanced Large Language Models' instruction-following capabilities into smaller models using a selected subset has become a mainstream approach in model training. While existing synthetic instruction data selection strategies rely mainly on single-dimensional signals (i.e., reward scores, model perplexity), they fail to capture the complexity of instruction-following across diverse fields. Therefore, we investigate more diverse signals to capture comprehensive instruction-response pair characteristics and propose three foundational metrics that leverage Multi-LLM wisdom, informed by (1) diverse LLM responses and (2) reward model assessment. Building upon base metrics, we propose CrowdSelect, an integrated metric incorporating a clustering-based approach to maintain response diversity. Our comprehensive experiments demonstrate that our foundation metrics consistently improve performance across 4 base models on MT-bench and Arena-Hard. CrowdSelect, efficiently incorporating all metrics, achieves state-of-the-art performance in both Full and LoRA fine-tuning, showing improvements of 4.81% on Arena-Hard and 11.1% on MT-bench with Llama-3.2-3b-instruct. We hope our findings will bring valuable insights for future research in this direction. Code are available at https://github.com/listentm/crowdselect.