AI Prompt to Build a Golden Test Set for Evaluating RAG Retrieval Accuracy
This RAG test set prompt helps you generate a golden evaluation set for a retrieval-augmented generation pipeline, built for developers and ML engineers who need to measure retrieval quality instead of guessing from a handful of manual spot checks. You feed the model a batch of source documents, and it produces question-answer pairs tied to specific passages, along with the exact source text each answer should come from.
The prompt works by asking the model to read each document chunk and invent realistic user questions that a retrieval system should be able to answer using only that chunk, plus a few adversarial questions designed to have no good answer in the corpus. This mix lets you test both retrieval precision (does the right chunk get retrieved) and the system's ability to say "I don't know" when nothing relevant exists. Running this periodically as your knowledge base grows catches retrieval drift before users notice it.
If you're assembling this test set from a large batch of PDFs, contracts, or support docs, pulling only the relevant passages first with Context Extractor makes it easier to generate accurate, source-grounded question-answer pairs instead of working from whole documents at once.
Prompt template
Want it sharper? Optimize this prompt with Prompt Optimizer, check it with the Prompt Debugger or shorten it with the Token Optimizer.
Example input
When to use it
- You're launching a new RAG pipeline and have no baseline for retrieval accuracy
- Your knowledge base has grown and you suspect older queries no longer retrieve the right chunks
- You need a repeatable benchmark to compare two chunking or embedding strategies
- You're debugging user complaints about wrong or missing answers from a RAG assistant
Best practices
- Generate questions from a representative sample of documents, not just your longest or most detailed ones
- Include a deliberate share of unanswerable questions to test refusal behavior, not just correct retrieval
- Have a human spot-check a sample of generated Q&A pairs before trusting the set as ground truth
- Re-run the test set after any change to chunk size, embedding model, or reranking logic
Common mistakes
- Only testing easy, single-fact questions that don't reflect how real users phrase queries
- Generating the test set from the same documents used to tune the retrieval system, which hides overfitting
- Treating a one-time test set as permanent instead of refreshing it as content changes
- Skipping unanswerable questions, so the system's hallucination rate never gets measured
FAQs
What is a golden test set in RAG?
A golden test set is a curated collection of questions paired with known-correct answers and source passages, used as a benchmark to measure whether a retrieval-augmented generation system retrieves and answers accurately over time.
How many test questions do I need to evaluate a RAG pipeline?
There's no fixed number, but most teams start with 50-100 questions covering a representative mix of document types, question styles, and at least 10-15% unanswerable questions to test refusal behavior.
Can ChatGPT or Claude generate realistic test questions from my documents?
Yes, both can generate question-answer pairs grounded in a provided document when given clear instructions and the source text, though a human should still review a sample before treating the output as ground truth.
Which Cuelara tool can help me prepare documents before building this test set?
Context Extractor — it pulls only the relevant passages from large PDFs or CSVs first, which makes it easier to generate accurate, source-grounded test questions from big document sets.