RAGTUM at SemEval-2026 Task 8: Contextual Query Rewriting and Dense Retrieval for Multi-Turn RAG
Summary
The RAGTUM system, presented at SemEval-2026 Task 8, addresses the inherent challenges of multi-turn Retrieval-Augmented Generation (RAG) by combining context-aware query rewriting with a dense retrieval strategy. Developed by a team from the TUM practical course, this system implements a robust pipeline. It begins by cleansing noisy corpora to ensure data quality. Subsequently, it utilizes dense OpenAI embeddings, managed through Milvus, for highly robust information retrieval. For both standalone query generation and the final response synthesis, RAGTUM employs models from the Gemini 2.5 flash family. This integrated approach effectively demonstrates the power of combining high-precision retrieval with fact-based generation across diverse domains, as detailed in pages 1784–1790 of the workshop proceedings.
Key takeaway
For Machine Learning Engineers building multi-turn RAG systems, this work highlights a practical architecture to improve conversational AI. You should consider implementing context-aware query rewriting to maintain conversational coherence and integrate dense retrieval using tools like Milvus with OpenAI embeddings for robust information access. Furthermore, exploring the Gemini 2.5 flash family of models for both query generation and final response synthesis could significantly enhance your system's fact-based generation capabilities across varied domains.
Key insights
The RAGTUM system enhances multi-turn RAG via context-aware query rewriting and dense retrieval with specific model and embedding choices.
Principles
- Context-aware query rewriting improves multi-turn RAG.
- Dense retrieval enhances RAG robustness.
- Corpora cleansing is crucial for RAG quality.
Method
The RAGTUM pipeline cleanses noisy corpora, uses dense OpenAI embeddings via Milvus for retrieval, and employs Gemini 2.5 flash models for query generation and response synthesis.
In practice
- Integrate query rewriting for conversational RAG.
- Use Milvus with dense embeddings for retrieval.
- Consider Gemini 2.5 flash for RAG synthesis.
Topics
- Multi-Turn RAG
- Contextual Query Rewriting
- Dense Retrieval
- OpenAI Embeddings
- Milvus Vector Database
- Gemini 2.5 Flash
Best for: AI Engineer, Research Scientist, AI Scientist, Machine Learning Engineer, NLP Engineer
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Editorial summary, takeaway, and curation by AIssential. Original article published by Paper Index on ACL Anthology.