Divide by Question, Conquer by Agent: SPLIT-RAG with Question-driven graph partitioning

Ruiyi Yang, Hao Xue, Imran Razzak, Shirui Pan, Hakim Hacid, Flora D. Salim


Abstract
Retrieval-augmented generation over knowledge graphs (KGs) can improve the factual grounding of large language models, but efficient retrieval remains challenging when the underlying graph is large and multi-hop evidence is distributed across different regions. We present **SPLIT-RAG**, an efficiency-oriented multi-agent KG-RAG framework that organises a KG into reusable, question-aligned partitions using reasoning patterns observed in training questions. At inference time, SPLIT-RAG forms a query-specific retrieval plan, activates only a small set of relevant partition-specialised agents, and aggregates their retrieved evidence before final answer generation. To improve reliability when evidence from different agents is combined, the framework applies compatibility-based filtering over retrieved triples prior to synthesis. Experiments on WebQSP, CWQ, and MetaQA show that SPLIT-RAG achieves strong performance against recent KG+LLM baselines while reducing end-to-end latency under matched budgets. Component ablations and model-tier analyses further show that selective multi-agent retrieval is central to the performance gain, and that lightweight retrieval agents paired with a stronger head agent provide an effective accuracy–latency trade-off.
Anthology ID:
2026.emnlp-main.2110
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
48009–48026
Language:
URL:
https://aclanthology.org/2026.emnlp-main.2110/
DOI:
Bibkey:
Cite (ACL):
Ruiyi Yang, Hao Xue, Imran Razzak, Shirui Pan, Hakim Hacid, and Flora D. Salim. 2026. Divide by Question, Conquer by Agent: SPLIT-RAG with Question-driven graph partitioning. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 48009–48026, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Divide by Question, Conquer by Agent: SPLIT-RAG with Question-driven graph partitioning (Yang et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.2110.pdf