Retrieval-Augmented Generation (RAG)
Concept combining information retrieval with generative language models to provide more factual and up-to-date responses.
Classification
- ComplexityMedium
- Impact areaTechnical
- Decision typeArchitectural
- Organizational maturityIntermediate
Technical context
Principles & goals
Use cases & scenarios
Compromises
- Hallucinations still possible with poor retrieval
- Confidentiality concerns with sensitive sources
- Complexity in permissions and governance models
- Always attach source citations and use verifiable quotes.
- Regularly retrain or reindex retrieval models with fresh data.
- Iteratively refine prompt templates and ranker metrics.
I/O & resources
- Document corpus or data sources (indexable)
- Embedding models or feature extractors
- Large language model / generative model
- Generated answers with source citations
- Ranked retrieval sets and scores
- Logging and evaluation metrics for monitoring
Description
Retrieval-Augmented Generation (RAG) combines external information retrieval with large language models to produce more factual and up-to-date responses. The concept integrates search, indexing and reranking components with generative models and defines interfaces, evaluation criteria and governance for knowledge-intensive applications. RAG addresses answer accuracy and timeliness.
✔Benefits
- Improved factuality via external sources
- Freshness without full model retraining
- Better control over answer sources
✖Limitations
- Dependence on index quality and coverage
- Risk of inconsistent source integration
- Latency introduced by retrieval steps
Trade-offs
Metrics
- Answer accuracy (Factuality)
Share of answers supported by verifiable sources.
- Retrieval relevance (Recall@K)
Percentage of relevant documents within top-K results.
- End-to-end latency
Time from request to final answer including retrieval and generation.
Examples & implementations
Knowledge-backed Chatbots
Chatbot uses internal document index and RAG for precise answer generation.
Expert Research Assistance
RAG assists analysts with aggregated, source-based answers from multiple repositories.
Combination with Retrieval-as-a-Service
Integration of external vector databases to improve retrieval quality.
Implementation steps
Analyze corpus and identify relevant sources.
Set up indexing and embedding pipeline.
Integrate retrieval component and train/configure ranker.
Implement LLM integration, run tests and set up monitoring.
⚠️ Technical debt & bottlenecks
Technical debt
- Monolithic indices without partitioning cause scaling issues
- Hardcoded prompts and missing test suites for answers
- Insufficient data versioning in knowledge sources
Known bottlenecks
Misuse examples
- Exposing sensitive internal content via generated answers
- Using outdated indices without reindexing
- Replacing human review in safety-critical answers
Typical traps
- Underestimating costs for embedding generation and storage
- Difficulties in source attribution management
- Lack of monitoring for drift in retrieval performance
Required skills
Architectural drivers
Constraints
- • Limited index size or cost constraints
- • Compliance requirements for source data
- • Compute and storage needs for embedding generation