Skip to content
Open access

CultRAG at SemEval-2026 Task 7: Hybrid Sparse-Dense Retrieval with Entity-Centric Knowledge Bases for Cultural MCQ Answering

2026 · SemEval@ACL · pp. 3137-3142 · 1 citation · 11 references
Computer Science

TL;DR

The core finding is that RAG hurts rather than helps: the LLM-only baseline achieves 78.6% accuracy, outperforming the full system at 78.5% (McNemar’s test, p = 0 . 962).

Abstract

We present a trust-weighted Retrieval-Augmented Generation (RAG; Lewis et al., 2020) system for SemEval-2026 Task 7 (BLEnD) Track 2 (Ousidhoum et al., 2026), targeting English cultural multiple-choice QA across 30 countries. Built atop Llama-3.1-8B-Instruct (Meta AI, 2024), the six-phase pipeline integrates hybrid BM25+FAISS retrieval, country-aware filtering, intent detection, tiered routing, anti-leak prompt engineering, and trust-weighted reranking. The core finding is that RAG hurts rather than helps: the LLM-only baseline achieves 78.6% accuracy, outperforming the full system at 78.5% (McNemar’s test, p = 0 . 962 ). Oracle analysis reveals that only 40.7% of questions are answerable from the knowledge base, explaining why retrieval introduces more noise than signal. The sole recovery comes from anti-leak prompt filtering (Phase 4), which mitigates answer-anchoring artifacts. Code: https://github.com/CultRAG/ BLEnD-CultRAG .

Read PDF

Similar papers

Preprint Aug 2026

SciRet: A Compute-Aware Empirical Study of Retrieval and Reranking for Scientific RAG

We introduce SciRet, a compute-aware empirical study of retrieval-augmented generation for scientific question answering over CORD-19. Rather than proposing a new model, we evaluate a fixed scientific RAG pipeline across three corpus scales: 1,034 chunks (1K papers), 5,160 chunks (5K papers), and 15,480 chunks (15K pap...

Kaysarul Anas Apurba, Mahade Hasan, Rofiqul Alam Shehab et al. · 0 citations
Book Open access Jul 2026

Effectiveness of Sparse Retrieval for Automated Fact-Checking

These findings establish learned sparse retrieval as a highly impactful design choice in automated fact-checking, with retrieval quality serving as a critical determinant of end-to-end performance in the studied systems.

Ritvik Setty, Vinay Setty · 0 citations
Preprint Jul 2026

Cross-Architecture LLM Ensembles, Feature-Based Reranking and Retrieval-Augmented Prompting for Legal Information Processing

Overall, legal information processing benefits from different inductive biases across tasks, with cross-architecture ensembling, feature-based reranking and retrieval-augmented prompting each proving most effective in different settings.

Amal Saad Alshehri, N. Bencomo, Amir Atapour-Abarghouei · 0 citations
Review Open access Jul 2026

Retrieval-Augmented Generation for Trustworthy Enterprise LLM Assistants

This paper presents a technical synthesis of RAG for trustworthy enterprise assistants and describes the end-to-end pipeline in full: document chunking, embedding, vector indexing, retrieval, cross-encoder re-ranking, and grounded generation with inline citations.

Bini P. B. · 0 citations
Open access Jul 2026

ADAPTIVE MULTI-STAGE VECTOR RETRIEVAL FOR RETRIEVAL-AUGMENTED GENERATION

The Adaptive Multi-Stage Vector Retrieval (AMSVR) framework is proposed, prioritising weighted, drift-resistant composition over uniform fusion, and offers tailored configurations: AMSVR-Scientific (dense + tuned hybrid) peaks at NDCG@10 = 0.7570 on SciFact, while AMSVR-Full (seven stages) targets broader, noisier corp...

Samsudeen Alabi Bankole, Yakub Kayode Saheed · 0 citations

We use cookies to run the site and, with your consent, for analytics and to show ads. See our Cookie Policy.