Retrieval-Augmented Generation (RAG)

Grounding

Definition

Grounding is the practice of providing an LLM with specific source material — retrieved documents, database records, tool outputs — and instructing it to base its response on that material rather than generating from internal parametric knowledge alone. A grounded response cites, references, or directly draws from the provided context, making it verifiable. RAG is the primary technical mechanism for grounding: by retrieving relevant documents and inserting them into the prompt context, RAG grounds the model's response in specific source material. Grounding is the countermeasure to hallucination — it gives the model accurate, current information to work from instead of relying on potentially stale or incorrect training data.

Why It Matters

Grounding is essential for enterprise AI applications where accuracy matters. An ungrounded LLM drawing purely from training data may confidently state outdated pricing, describe deprecated features, or invent company policies that do not exist. A grounded RAG system constrained to its knowledge base content can only reference information that has been reviewed and published by the organization. This control over the information source is precisely why enterprise customers choose RAG architectures — it brings organizational knowledge into the AI response loop and keeps the AI accountable to specific, auditable sources.

How It Works

Grounding is achieved through a combination of architecture and prompt design. Architecture: retrieve relevant documents and include them in the LLM context window. Prompt design: explicitly instruct the model to stay within the provided context ('Answer only based on the information provided below. Do not use any external knowledge.'). Grounding quality is measured by faithfulness scores — what fraction of claims in the generated response can be traced to the provided context. Citation generation (asking the model to cite specific passages) makes grounding explicit and verifiable. Confidence calibration (expressing uncertainty when context is ambiguous) is also part of grounding behavior.

Grounding — Grounded vs Ungrounded Responses

Ungrounded

LLM memory only

Answer:

You can reset your password from Settings. Resets are valid for 48 hours and support can extend them on request.

XFrom Settings — no source
XValid for 48 hours — no source
XSupport can extend — no source
Grounding score0 / 3 = 0%

Grounded

RAG retrieved

Answer:

Click Forgot Password on the login page [1]. Links expire after 24 hours [2]. A confirmation email is sent immediately [2].

Sources Used

[1]Login page has Forgot Password link
[2]Reset links expire in 24h; email sent
Grounding score3 / 3 = 100%

Query: “How do I reset my password?”

Real-World Example

A 99helpers customer implements a grounding framework for their AI chatbot. Every response is generated with the instruction: 'Use only the information in the CONTEXT section to answer. If the answer is not clearly present, say: I do not have specific information about this in my knowledge base, but I can connect you with a human agent who can help.' After implementing this grounding prompt, the rate of customer follow-ups saying 'the chatbot gave me wrong information' drops from 9% of interactions to 1.2%.

Common Mistakes

  • Grounding without evaluating faithfulness — a grounded architecture does not guarantee grounded responses; measure faithfulness scores to verify the model actually uses provided context
  • Over-constraining the model to the context — some questions benefit from the model's general reasoning ability; excessively strict grounding prompts can make responses robotic
  • Treating grounding as a replacement for good retrieval — grounding only helps if the relevant information is in the retrieved context; poor retrieval = poor grounding = poor answers

Related Terms

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