Journal of Computer Applications ›› 2026, Vol. 46 ›› Issue (9): 2838-2846.DOI: 10.11772/j.issn.1001-9081.2025080969

• Data science and technology • Previous Articles    

Fair recommendation framework for large language models with sensitive attribute absence

Zhenhui GONG1,2, Xiaoyu SHI1,2(), Yun LU1,2, Yangcheng LIU3, Mingsheng SHANG1,2   

  1. 1.Chongqing Institute of Green and Intelligent Technology,Chinese Academy of Sciences,Chongqing 400714,China
    2.Chongqing School,University of Chinese Academy of Sciences,Chongqing 400714,China
    3.North China Institute of Computing Technology,Beijing 100083,China
  • Received:2025-08-26 Revised:2025-11-03 Accepted:2025-11-07 Online:2025-11-17 Published:2026-09-10
  • Contact: Xiaoyu SHI
  • About author:GONG Zhenhui, born in 2000, M. S. candidate. His researchinterests include deep learning, reinforcement learning, recommender systems, group fairness.
    SHI Xiaoyu,born in 1986, Ph. D., associate research fellow. Hisresearch interests include reinforcement learning, edge computing, big data mining.
    LU Yun,born in 2002, M. S. candidate. Her research interestsinclude deep learning, reinforcement learning, recommender systems,item fairness.
    LIU Yangcheng,born in 1980, M. S., research fellow. Hisresearch interests include big data mining, geographic information platform, graphics and image. SHANG Mingsheng, born
    SHANG Mingsheng,born in 1973, Ph. D., research fellow. Hisresearch interests include big data, artificial intelligence, internet of things, cloud computing.

面向敏感属性缺失的大语言模型公平推荐框架

龚镇辉1,2, 史晓雨1,2(), 鲁云1,2, 刘阳成3, 尚明生1,2   

  1. 1.中国科学院 重庆绿色智能技术研究院,重庆 400714
    2.中国科学院大学 重庆学院,重庆 400714
    3.华北计算技术研究所,北京 100083
  • 通讯作者: 史晓雨
  • 作者简介:龚镇辉(2000—),男,福建漳州人,硕士研究生,主要研究方向:深度学习、强化学习、推荐系统、群体公平性
    史晓雨(1986—),男,河南南阳人,副研究员,博士,主要研究方向:强化学习、边缘计算、大数据挖掘
    鲁云(2002—),女,湖北武汉人,硕士研究生,主要研究方向:深度学习、强化学习、推荐系统、物品公平性
    刘阳成(1980—),男,河南南阳人,研究员,硕士,主要研究方向:大数据挖掘、地理信息平台、图形图像
    尚明生(1973—),男,重庆人,研究员,博士,主要研究方向:大数据、人工智能、物联网、云计算。
  • 基金资助:
    重庆市科技创新重大研发项目(CSTB2023TIAD-STX0031)

Abstract:

Large Language Models (LLMs) bring enhanced semantic understanding and personalized recommendation capabilities to recommender systems, however, they face significant challenges in user fairness in practical applications. The existing methods for LLM-based fair recommendation often rely on explicit sensitive attributes for constraints or reweighting, making them difficult to apply in scenarios where such attributes are unavailable due to privacy protection or inaccessibility. To address this issue, an FAIR recommendation framework for large language models with Sensitive Attribute Absence (FAIR-SAA) was proposed. In this framework, recommendation fairness was enhanced without accessing sensitive attributes through dynamic prompt optimization and adversarial reweighting. Specifically, in the first stage, a dynamic prompt optimization strategy was adopted to identify high-loss samples during the fine-tuning process, and these samples were utilized as contextual examples to mitigate stereotypical patterns; in the second stage, an adversarial reweighting mechanism was introduced to focus on underperforming regions of the model dynamically, thereby increasing the impact of underrepresented samples on model updates. Experimental results on three public datasets such as MovieLens-1M show that FAIR-SAA reduces the gender group Normalized Discounted Cumulative Gain NDCG@10 and Hit Ratio HR@10 by 74.47% and 61.76%, averagely, with a recommendation accuracy maintained comparable to baseline recommendation accuracy of the BI-step Grounding Paradigm for Recommendation (BIGRec). When BIGRec is used as the base recommendation model, even when compared with Fairness-Aware Conformal Thresholding and Prompt EngineeRing (FACTER) framework, a fair recommendation method with full access to sensitive attributes, FAIR-SAA is competitive with 58.33% fairness metric. It can be seen that FAIR-SAA provides an effective solution to recommendation fairness problem in real-world privacy-preserving scenarios.

Key words: recommender system, Large Language Model (LLM), group fairness, sensitive attribute absence, privacy protection

摘要:

大语言模型(LLM)为推荐系统带来了更强的语义理解和个性化推荐能力,但它在实际应用中面临着严重的用户公平性挑战。现有LLM公平推荐方法多依赖于用显式敏感属性进行约束或重加权,在用户敏感属性因隐私保护或不可获取而缺失的场景下,通常难以适用。针对这一问题,提出一种敏感属性无关的LLM公平推荐框架(FAIR-SAA)。该框架通过动态提示优化与对抗重加权方法,在无须访问敏感属性的情况下实现推荐公平性提升。具体而言,在第一阶段,采用动态提示优化策略,在微调过程中识别高损失样本,将它作为上下文示例以缓解刻板印象模式;在第二阶段,引入对抗重加权机制动态关注模型表现不佳的分布区域,从而增强代表性不足样本对模型更新的影响。在MovieLens-1M等3个公开数据集上的实验结果表明,FAIR-SAA在保持推荐精度与双阶段语义对齐推荐范式(BIGRec)模型基线推荐精度相当的同时,将性别群体的归一化折损累积增益NDCG@10与命中率HR@10平均降低74.47%与61.76%;即便与敏感属性完全可见的公平推荐方法面向公平性的共形阈值与提示工程(FACTER)框架相比,在以BIGRec为基础推荐模型的情况下,FAIR-SAA在58.33%的公平性指标上仍具竞争力。FAIR-SAA为现实环境下隐私保护场景中的推荐公平性问题提供了一种有效的解决方案。

关键词: 推荐系统, 大语言模型, 群体公平性, 敏感属性缺失, 隐私保护

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