Post

TRAG meets GNNs

TRAG meets GNNs: Integrating graphs into a modern workflow.

Knowledge Graphs (KGs) are a powerful way to represent factual knowledge, but querying them with natural language is challenging.

And Graph Neural Networks (GNNs) excel at reasoning over KGs, something Large Language Models (LLMs) are still struggling with.

There has been a lot of work in combining these two approaches lately, but it doesnโ€™t feel like weโ€™ve found the right recipe yet.

By leaning into the popular Retrieval-augmented Generation (RAG) trend, GNN-RAG tries to change this.

The idea is for the GNN to handle the complex graph structure, while the LLM leverages its language understanding to produce the final answer.

๐Ÿค” Vanilla-RAG struggles with structured knowledge sources like knowledge graphs. GNN-RAG is a very neat idea to fix this!

โ›ณ Vanilla-RAG struggles with structured inputs like KGs because it relies heavily on LLMs for retrieval, which are not adept at handling the complex graph information inherent in KGs. This leads to suboptimal performance, especially on multi-hop and multi-entity questions that require traversing multiple relationships in the graph.

โ›ณ GNN-RAG integrates the strengths of both LLMs and and Graph Neural Networks (GNNs) to solve this issue:

  • ๐Ÿ’ก GNN: Excels at processing and reasoning over graph structures. It reasons over a dense KG subgraph to retrieve answer candidates for a given question.
  • ๐Ÿ’กLLM: Leverages its natural language processing abilities to further reason over the information provided by the GNN.

๐Ÿ‘‰ Hereโ€™s the workflow:

  • ๐Ÿ”บ A GNN processes the KG to identify and retrieve candidate answers.
  • ๐Ÿ”บThe shortest paths connecting question entities to answer candidates in the KG are extracted to represent reasoning paths.
  • ๐Ÿ”บThese paths are verbalized and provided as input to the LLM for final reasoning and answer generation.

GNN-RAG achieves state-of-the-art performance on two major KGQA benchmarks, even outperforming GPT-4 in some cases.

GNN-RAG achieves state-of-the-art results on two widely used KGQA benchmarks, WebQSP and ComplexWebQuestions (CWQ) and outperforms existing methods, including GPT-4, particularly on multi-hop and multi-entity questions.

It particularly seems to shine on challenging multi-hop and multi-entity questions.

๐Ÿง™Paper Authors: Costas Mavromatis, George Karypis 1Minnesota University

 GNN-RAG architecture

Translate to Korean

RAG์™€ GNN์˜ ๋งŒ๋‚จ: ๊ทธ๋ž˜ํ”„๋ฅผ ์ตœ์‹  ์›Œํฌํ”Œ๋กœ์šฐ์— ํ†ตํ•ฉํ•ฉ๋‹ˆ๋‹ค.

์ง€์‹ ๊ทธ๋ž˜ํ”„(KG)๋Š” ์‚ฌ์‹ค์— ์ž…๊ฐํ•œ ์ง€์‹์„ ํ‘œํ˜„ํ•˜๋Š” ๊ฐ•๋ ฅํ•œ ๋ฐฉ๋ฒ•์ด์ง€๋งŒ ์ž์—ฐ์–ด๋กœ ์ฟผ๋ฆฌํ•˜๋Š” ๊ฒƒ์€ ์–ด๋ ต์Šต๋‹ˆ๋‹ค.

๊ทธ๋ฆฌ๊ณ  ๊ทธ๋ž˜ํ”„ ์‹ ๊ฒฝ๋ง(GNN)์€ ๋Œ€๊ทœ๋ชจ ์–ธ์–ด ๋ชจ๋ธ(LLM)์ด ์—ฌ์ „ํžˆ ์–ด๋ ค์›€์„ ๊ฒช๊ณ  ์žˆ๋Š” KG๋ณด๋‹ค ์ถ”๋ก ํ•˜๋Š” ๋ฐ ํƒ์›”ํ•ฉ๋‹ˆ๋‹ค.

์ตœ๊ทผ ์ด ๋‘ ๊ฐ€์ง€ ์ ‘๊ทผ ๋ฐฉ์‹์„ ๊ฒฐํ•ฉํ•˜๋Š” ๋ฐ ๋งŽ์€ ์ž‘์—…์ด ์žˆ์—ˆ์ง€๋งŒ ์•„์ง ์˜ฌ๋ฐ”๋ฅธ ๋ ˆ์‹œํ”ผ๋ฅผ ์ฐพ์ง€ ๋ชปํ•œ ๊ฒƒ ๊ฐ™์Šต๋‹ˆ๋‹ค.

GNN-RAG๋Š” ์ธ๊ธฐ ์žˆ๋Š” RAG(Retrieval-augmented Generation) ์ถ”์„ธ์— ๊ธฐ๋Œ€์–ด ์ด๋ฅผ ๋ฐ”๊พธ๋ ค๊ณ  ํ•ฉ๋‹ˆ๋‹ค.

์•„์ด๋””์–ด๋Š” GNN์ด ๋ณต์žกํ•œ ๊ทธ๋ž˜ํ”„ ๊ตฌ์กฐ๋ฅผ ์ฒ˜๋ฆฌํ•˜๋Š” ๋ฐ˜๋ฉด, LLM์€ ์–ธ์–ด ์ดํ•ด๋ฅผ ํ™œ์šฉํ•˜์—ฌ ์ตœ์ข… ๋‹ต๋ณ€์„ ์ƒ์„ฑํ•˜๋Š” ๊ฒƒ์ž…๋‹ˆ๋‹ค.

๐Ÿค” Vanilla-RAG๋Š” ์ง€์‹ ๊ทธ๋ž˜ํ”„์™€ ๊ฐ™์€ ๊ตฌ์กฐํ™”๋œ ์ง€์‹ ์†Œ์Šค๋กœ ์–ด๋ ค์›€์„ ๊ฒช๊ณ  ์žˆ์Šต๋‹ˆ๋‹ค. GNN-RAG๋Š” ์ด ๋ฌธ์ œ๋ฅผ ํ•ด๊ฒฐํ•˜๊ธฐ ์œ„ํ•œ ๋งค์šฐ ๊น”๋”ํ•œ ์•„์ด๋””์–ด์ž…๋‹ˆ๋‹ค!

โ›ณ Vanilla-RAG๋Š” KG์— ๋‚ด์žฌ๋œ ๋ณต์žกํ•œ ๊ทธ๋ž˜ํ”„ ์ •๋ณด๋ฅผ ์ฒ˜๋ฆฌํ•˜๋Š” ๋ฐ ๋Šฅ์ˆ™ํ•˜์ง€ ์•Š์€ LLM์— ํฌ๊ฒŒ ์˜์กดํ•˜๊ธฐ ๋•Œ๋ฌธ์— KG์™€ ๊ฐ™์€ ๊ตฌ์กฐํ™”๋œ ์ž…๋ ฅ์— ์–ด๋ ค์›€์„ ๊ฒช์Šต๋‹ˆ๋‹ค. ์ด๋กœ ์ธํ•ด ์„ฑ๋Šฅ์ด ์ตœ์ ํ™”๋˜์ง€ ์•Š์œผ๋ฉฐ, ํŠนํžˆ ๊ทธ๋ž˜ํ”„์—์„œ ์—ฌ๋Ÿฌ ๊ด€๊ณ„๋ฅผ ์ˆœํšŒํ•ด์•ผ ํ•˜๋Š” ๋‹ค์ค‘ ํ™‰ ๋ฐ ๋‹ค์ค‘ ์—”ํ„ฐํ‹ฐ ์งˆ๋ฌธ์—์„œ ์„ฑ๋Šฅ์ด ์ €ํ•˜๋ฉ๋‹ˆ๋‹ค.

โ›ณ GNN-RAG๋Š” ์ด ๋ฌธ์ œ๋ฅผ ํ•ด๊ฒฐํ•˜๊ธฐ ์œ„ํ•ด LLM๊ณผ ๊ทธ๋ž˜ํ”„ ์‹ ๊ฒฝ๋ง(GNN)์˜ ๊ฐ•์ ์„ ํ†ตํ•ฉํ•ฉ๋‹ˆ๋‹ค.

  • ๐Ÿ’ก GNN: ๊ทธ๋ž˜ํ”„ ๊ตฌ์กฐ์— ๋Œ€ํ•œ ์ฒ˜๋ฆฌ ๋ฐ ์ถ”๋ก ์— ํƒ์›”ํ•ฉ๋‹ˆ๋‹ค. ์กฐ๋ฐ€ํ•œ KG ํ•˜์œ„ ๊ทธ๋ž˜ํ”„๋ฅผ ํ†ตํ•ด ์ถ”๋ก ํ•˜์—ฌ ์ฃผ์–ด์ง„ ์งˆ๋ฌธ์— ๋Œ€ํ•œ ๋‹ต๋ณ€ ํ›„๋ณด๋ฅผ ๊ฒ€์ƒ‰ํ•ฉ๋‹ˆ๋‹ค.
  • ๐Ÿ’กLLM: ์ž์—ฐ์–ด ์ฒ˜๋ฆฌ ๊ธฐ๋Šฅ์„ ํ™œ์šฉํ•˜์—ฌ GNN์—์„œ ์ œ๊ณตํ•˜๋Š” ์ •๋ณด๋ฅผ ์ถ”๊ฐ€๋กœ ์ถ”๋ก ํ•ฉ๋‹ˆ๋‹ค.

๐Ÿ‘‰ ์›Œํฌํ”Œ๋กœ๋Š” ๋‹ค์Œ๊ณผ ๊ฐ™์Šต๋‹ˆ๋‹ค.

  • ๐Ÿ”บ GNN์€ KG๋ฅผ ์ฒ˜๋ฆฌํ•˜์—ฌ ํ›„๋ณด ๋‹ต๋ณ€์„ ์‹๋ณ„ํ•˜๊ณ  ๊ฒ€์ƒ‰ํ•ฉ๋‹ˆ๋‹ค.
  • ๐Ÿ”บKG์˜ ํ›„๋ณด์ž์—๊ฒŒ ๋‹ต๋ณ€ํ•˜๊ธฐ ์œ„ํ•ด ์งˆ๋ฌธ ์—”ํ„ฐํ‹ฐ๋ฅผ ์—ฐ๊ฒฐํ•˜๋Š” ์ตœ๋‹จ ๊ฒฝ๋กœ๊ฐ€ ์ถ”์ถœ๋˜์–ด ์ถ”๋ก  ๊ฒฝ๋กœ๋ฅผ ๋‚˜ํƒ€๋ƒ…๋‹ˆ๋‹ค.
  • ๐Ÿ”บ์ด๋Ÿฌํ•œ ๊ฒฝ๋กœ๋Š” ์–ธ์–ดํ™”๋˜์–ด ์ตœ์ข… ์ถ”๋ก  ๋ฐ ๋‹ต๋ณ€ ์ƒ์„ฑ์„ ์œ„ํ•ด LLM์— ์ž…๋ ฅ์œผ๋กœ ์ œ๊ณต๋ฉ๋‹ˆ๋‹ค.

GNN-RAG๋Š” ๋‘ ๊ฐ€์ง€ ์ฃผ์š” KGQA ๋ฒค์น˜๋งˆํฌ์—์„œ ์ตœ์ฒจ๋‹จ ์„ฑ๋Šฅ์„ ๋‹ฌ์„ฑํ•˜๋ฉฐ ๊ฒฝ์šฐ์— ๋”ฐ๋ผ GPT-4๋ฅผ ๋Šฅ๊ฐ€ํ•˜๊ธฐ๋„ ํ•ฉ๋‹ˆ๋‹ค.

GNN-RAG๋Š” ๋„๋ฆฌ ์‚ฌ์šฉ๋˜๋Š” ๋‘ ๊ฐ€์ง€ KGQA ๋ฒค์น˜๋งˆํฌ์ธ WebQSP ๋ฐ ComplexWebQuestions(CWQ)์—์„œ ์ตœ์ฒจ๋‹จ ๊ฒฐ๊ณผ๋ฅผ ๋‹ฌ์„ฑํ•˜๊ณ  ํŠนํžˆ ๋‹ค์ค‘ ํ™‰ ๋ฐ ๋‹ค์ค‘ ์—”ํ„ฐํ‹ฐ ์งˆ๋ฌธ์—์„œ GPT-4๋ฅผ ํฌํ•จํ•œ ๊ธฐ์กด ๋ฐฉ๋ฒ•์„ ๋Šฅ๊ฐ€ํ•ฉ๋‹ˆ๋‹ค.

ํŠนํžˆ ๋„์ „์ ์ธ ๋‹ค์ค‘ ํ™‰ ๋ฐ ๋‹ค์ค‘ ์—”ํ„ฐํ‹ฐ ์งˆ๋ฌธ์— ๋น›์„ ๋ฐœํ•˜๋Š” ๊ฒƒ ๊ฐ™์Šต๋‹ˆ๋‹ค.

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