Spread Preference Annotation: Direct Preference Judgment for Efficient LLM Alignment
Dongyoung Kim, Kimin Lee, Jinwoo Shin, Jaehyung Kim
TL;DR
<3-5 sentence high-level summary> SPA introduces Spread Preference Annotation, a method to align large language models with human preferences using only a small seed of labeled data. It combines direct preference judgments derived from model logits with iterative self-generated data expansion and a noise-aware self-refinement mechanism to spread human preference signals across iterations. The approach shows strong improvements on AlpacaEval 2.0 and MT-Bench with minimal ground-truth data, outperforming baselines that rely on external reward models or LLM-based judgments. SPA also demonstrates robustness across seeds and model families, indicating practical utility for data-scarce alignment tasks.
Abstract
Aligning large language models (LLMs) with human preferences becomes a key component to obtaining state-of-the-art performance, but it yields a huge cost to construct a large human-annotated preference dataset. To tackle this problem, we propose a new framework, Spread Preference Annotation with direct preference judgment (SPA), that boosts the alignment of LLMs using only a very small amount of human-annotated preference data. Our key idea is leveraging the human prior knowledge within the small (seed) data and progressively improving the alignment of LLM, by iteratively generating the responses and learning from them with the self-annotated preference data. To be specific, we propose to derive the preference label from the logits of LLM to explicitly extract the model's inherent preference. Compared to the previous approaches using external reward models or implicit in-context learning, we observe that the proposed approach is significantly more effective. In addition, we introduce a noise-aware preference learning algorithm to mitigate the risk of low quality within generated preference data. Our experimental results demonstrate that the proposed framework significantly boosts the alignment of LLMs. For example, we achieve superior alignment performance on AlpacaEval 2.0 with only 3.3% of the ground-truth preference labels in the Ultrafeedback data compared to the cases using the entire data or state-of-the-art baselines.
