KG-RAG: Knowledge-Graph-Augmented Retrieval

PyTorch LangChain RAG

Retrieval research · 2025–2026

Overview

Research on combining graph-structured knowledge with neural retrieval to provide large language models with relational context for multi-hop question answering.

My contribution
Retrieval pipeline and multi-hop reasoning design
Context
Natural Language Learning Lab · Undergraduate research
Focus
Grounding · Multi-hop reasoning · Retrieval precision

Problem

Standard retrieval-augmented generation retrieves flat text chunks by embedding similarity alone, which gives large language models little structured relational context. This can limit factual accuracy on multi-hop questions that require facts from several connected entities.

Context and Constraints

The work was conducted at the Natural Language Learning Lab, Jeonbuk National University, from February 2025 to February 2026 under Prof. Hyun-je Song. The research connected structured graph context with neural embedding spaces while examining retrieval quality and computational efficiency.

My Role

I designed and implemented the knowledge-graph retrieval pipeline and multi-hop reasoning mechanism as an undergraduate researcher. The wider research direction and resulting manuscript are lab work under Prof. Hyun-je Song.

System Architecture

QuestionEntity and relation cues
Hybrid retrievalGraph context + neural embeddings
Grounded responseMulti-hop evidence context

Technical Decisions

  • Structured plus semantic context: graph retrieval preserved relations that embedding similarity alone can miss.
  • Multi-hop traversal: connected evidence was assembled for questions requiring more than one factual link.
  • Ablation studies: embedding integration techniques were isolated to examine accuracy and computational-efficiency trade-offs.

Implementation

The research implementation used PyTorch and LangChain to integrate graph-derived context with embedding-based retrieval and pass connected evidence into the generation stage.

Evaluation and Validation

Systematic ablation studies compared embedding integration approaches with attention to accuracy and computational-efficiency trade-offs.

Results

The implemented pipeline supports multi-hop retrieval over a knowledge graph for grounded question-answering research.

Limitations and Lessons

Relational coverage and embedding quality need separate evaluation because either can become the retrieval bottleneck. Ablating the integration stages made those trade-offs easier to isolate.

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