让检索答案更真实反映大众观点,避免少数意见被掩盖。
WARP: Wasserstein-Aligned RAG for Population Opinions

- 用Wasserstein距离校准文档情感强度分布,保留观点顺序信息
- 在35K文档、156个查询上降低43%以上分布误差,响应快于1秒
- 适合需要公平呈现民意的问答系统,如舆情分析与政策研究
RAG系统常用于总结大量文档中的群体观点。用户问“人们对X怎么看?”系统返回看似共识的答案。但标准的top-k检索基于查询相似度,无法忠实反映整体观点分布,导致少数意见被忽略。现有方法如MMR和DPP虽提升多样性,但无目标分布可对齐;基于KL或JS散度的校准方法虽有目标,却将观点区间视为无序,混淆强正负态度代价相同。本文提出WARP,一种后检索校准算法,先恢复被掩盖的弱代表观点,再利用Wasserstein-1距离选择情感强度分布匹配总体目标的文档,捕捉观点顺序结构。针对密集、稀疏和可变候选集设计三种变体,在三个涵盖35,000文档、156个查询、26个实体的评论领域中,域适配变体至少降低43%分布误差,延迟低于1秒。生成效果也显著:五名法官组成的LLM小组在k ≤ 5时,86%偏好WARP生成的答案。
原文摘要 · Abstract (English)
RAG systems are increasingly used to summarize what large collections of documents say. A user asks "What do people think about X?" and receives an answer that reads as consensus. But standard top-k retrieval ranks documents by query similarity, not by how faithfully they represent the population, so minority views quietly disappear. Existing fixes fall short. Diversity re-rankers like MMR and DPP spread retrieved documents apart, but with no target distribution to aim for. Calibration methods based on KL or JS divergence do target one, yet treat opinion bins as unordered: confusing strong positive with strong negative costs no more than an adjacent-bin miss. We introduce WARP, a family of post-retrieval algorithms that calibrate retrieved evidence to the population's opinion distribution. WARP first recovers underrepresented opinions that cosine ranking may bury, then uses Wasserstein-1 distance to select documents whose sentiment-intensity distribution matches the population target, capturing the ordinal structure ignored by KL and JS divergence. We develop three variants for dense, sparse, and variable candidate pools, trading off calibration quality and speed. Across three review domains spanning 35K documents, 156 queries, and 26 entities, WARP's domain-matched variants reduce distributional error by at least 43% with sub-second latency. These gains carry through to generation: a five-judge LLM panel prefers WARP-generated answers in 86% of decided comparisons at k <= 5.
Thank you to arXiv for use of its open access interoperability. PaperDance 不是 arXiv 官方产品;中文卡片由大模型生成,请以原文为准。