Advancements in Knowledge Graphs for RAG

Aug 19, 2024

Lecture Notes: Graph Rag by Jonathan Larsson

Introduction

  • Speaker: Jonathan Larsson
  • Topic: Graph Rag - an LLM derived Knowledge Graph for Retrieval-Augmented Generation (RAG).
  • Teaser: Example from 'Behind the Tech' podcast will be discussed later.

Overview of Graph Rag

  • Definition: Graph Rag consists of a two-step process that includes indexing private data to create LLM-derived knowledge graphs and orchestration for better retrieval.
  • Key Components:
    • Indexing Process: Creates knowledge graphs that serve as LLM memory representations.
    • Orchestration Mechanism: Utilizes pre-built indices for enhanced RAG operations.

Key Differentiators of Graph Rag

  1. Enhanced Search Relevancy: Provides a holistic view of data semantics.
  2. New Analytical Scenarios: Enables scenarios requiring large context for data analysis, trend summarization, etc.

Baseline RAG vs. Graph Rag

  • Baseline RAG Process:
    • Chunk private datasets using embeddings.
    • Store in vector databases.
    • Perform nearest neighbor searches.
  • Graph Rag Process:
    • Analyzes text chunks and performs reasoning over sentences with LLM in a single pass.
    • Focuses on relationships and their strengths between entities rather than just named entities.

Knowledge Graph Creation

  • Entity Recognition: Named entity recognition enhanced by understanding relationships' semantics.
  • Weighted Relationships: Graphs can be generated which reflect richer semantics than traditional networks.
  • Graph Machine Learning: Allows semantic aggregations and the creation of granular filters for querying.

Use Cases for Graph Rag

  • Dataset question generation
  • Summarization and Q&A
  • Various analytical applications

Demonstration of Graph Rag

  • Data Set: 3,000 articles on the Russian-Ukrainian conflict.
  • Question Example: "What is Novorossiya and what are its targets?"
    • Baseline RAG: Failed to answer fully.
    • Improved RAG: Partially answered but lacked specifics on targets.
    • Graph Rag: Successfully identified specific targets with evidence and context.

Verification and Hallucination Reduction

  • Can evaluate generated responses for accuracy and grounding with independent verification agents.

Thematic Analysis with Graph Rag

  • Question Example: "What are the top five themes in the data?"
    • Baseline RAG: Inadequate thematic analysis.
    • Graph Rag: Provided accurate themes focused on the conflict.
  • Performance Metrics: Graph Rag used 50,000 tokens and took 71 seconds, but provided richer and correct answers.

Network Map Visualization

  • Visual representation of the knowledge graph of the dataset.
  • Identifies communities of related entities (e.g., soccer topics alongside war topics).

Additional Data Set Analysis

  • Kevin's Podcast Transcripts:
    • Utilized Graph Rag to analyze technology trends and topics discussed.
    • Demonstrated the capability of grouping episodes semantically.

Conclusion

  • Graph Rag represents a significant advancement in retrieval-augmented generation by providing deeper semantic understanding and better analytical capabilities.