Evaluating RAG Systems with Synthetic Data¶
Retrieval-Augmented Generation systems are powerful tools for building AI-powered question-answering applications. Creating a diverse dataset of question & answer pairs that includes complex queries will help you quickly evaluate your RAG pipeline and generate metrics.
Evaluation is crucial to understanding the performance of your RAG system and identifying areas for improvement. There are multiple parameters to consider when evaluating a RAG system, including but not limited to:
- Embedding model choice
- Retrieval method (BM25, VectorDB, hybrid)
- Reranking strategy
- Answer generation model
- Chunking strategy
Synthetic baseline data can help you evaluate your RAG system's performance across these parameters.
This guide demonstrates how to evaluate RAG systems using synthetic data, providing a practical approach to testing and improving your implementation.
If you are in a hurry, you can jump straight to the code implementation.
Table of Contents¶
Setup¶
Before getting started, ensure you have Python 3.10 or later installed.
Set up your environment using conda:
Install the required dependencies:
For this cookbook, we'll work with HuggingFace Docs as our RAG dataset.¶
RAG Implementation¶
RAG is implemented in the RAG class using RAGatouille as the backbone for retrieval, a library focuses on making ColBERT simple to use for developers.
We'll use the instructor library to interact with OpenAI's API for chat completions for structured outputs.
Code taken from Instructor's cookbook.
Pydantic classes structures the responses returned from OpenAI API.
To implement the RAG pipeline, we'll use the RAG class:
The RAG Class¶
rag: RAGPretrainedModel for ColBERT based retrieval.client: Instructor client to interact with OpenAI's API.
import instructor
from ragatouille import RAGPretrainedModel
from openai import OpenAI
class RAG:
def __init__(self, chunks):
self.rag = RAGPretrainedModel.from_pretrained("colbert-ir/colbertv2.0")
self.index_path = self.rag.index(index_name="my_index", collection=chunks)
self.client = instructor.from_openai(OpenAI())
Now we need search and answer methods to complete RAG pipeline.
search: Retrieve relevant documents based on the query.answer: Generate a response using the retrieved documents.
We'll use QuestionAnswer pydantic model to structure the data for validation and processing.
def search(self, question: str, top_k=3) -> Union[List[List[str]], List[str]]:
res = self.rag.search(question, k=top_k)
return [r["content"] for r in res]
def answer(self, question: str) -> QuestionAnswer:
docs = self.search(question)
context = "\n".join(docs)
return self.client.chat.completions.create(
model="gpt-4o",
temperature=0,
response_model=QuestionAnswer,
messages=[
{
"role": "system",
"content": "You are a world class algorithm to answer questions with correct and exact citations.",
},
{"role": "user", "content": f"{context}"},
{"role": "user", "content": f"Question: {question}"},
],
validation_context={"text_chunk": context},
)
And that's it! We have a complete RAG pipeline ready for evaluation.
Generating Synthetic Data¶
To evaluate the RAG pipeline, we need a diverse dataset of question-answer pairs based on the document chunks we processed earlier. Our objective is to generate two datasets:
- Questions: A set of questions based on the document chunks and different personas.
- Multi-hop Questions: A set of multi-hop questions that require reasoning across multiple document chunks.
Generating QA Pairs¶
We'll use the QAPipeline class from dria.factory to generate question-answer pairs based on the document chunks.
The QAPipeline Class¶
Import the QAPipeline class from dria.factory:
We define our simulation as:
AI developers and researchers learning Huggingface. Some focus on fine-tuning and post-training, others on RAG systems, retrieval problems, image models, or dataset work.
Description of simulation determines the backstories for the generated questions.
Along with it, we specify the persona for the pipeline.
A researcher that is concise and direct
Persona determines how answers are generated based on the context provided.
We'll use existing chunks as our context to generate questions.
Instead of using chunks directly, we are merging them as files, and using files as whole to boost pipelines ability to generate coherent questions.
pipeline = QAPipeline(dria).build(
simulation_description="AI developers and researchers learning Huggingface. "
"Some focus on fine-tuning and post-training, others on RAG systems, "
"retrieval problems, image models, or dataset work.",
num_samples=1,
persona="A HuggingFace expert that is concise and direct",
chunks=file_chunks,
)
We can now execute the pipeline to generate question-answer pairs.
async def run_qa_pipeline(dria: Dria, file_chunks):
await dria.initialize()
pipeline = QAPipeline(dria).build(
simulation_description="AI developers and researchers learning Huggingface. "
"Some focus on fine-tuning and post-training, others on RAG systems, "
"retrieval problems, image models, or dataset work.",
num_samples=1,
persona="A HuggingFace expert that is concise and direct",
chunks=file_chunks,
)
return await pipeline.execute(return_output=True)
Generating Multi-hop Questions¶
We'll use the MultiHopQuestion class from dria.factory to generate multi-hop questions that require reasoning across multiple document chunks.
The MultiHopQuestion Class¶
Unlike simple QA pairs, multi-hop questions require reasoning across multiple document chunks.
MultiHopQuestion class is a Singleton, not a pipeline. It's a single atomic task so we'll use it with our ParallelSingletonExecutor.
Import the MultiHopQuestion class from dria.factory:
We'll initialize selected singleton and pass it to the ParallelSingletonExecutor for execution.
We set the model pools for the executor, publishing tasks to nodes that work with the specified models.
executor.set_models([Model.GPT4O, Model.GEMINI_15_FLASH, Model.QWEN2_5_32B_FP16, Model.GEMINI_15_FLASH])
Then load the instructions for the executor. We'll randomly sample 3 chunks from each file to create multi-hop questions.
Here is the complete code to generate multi-hop questions:
async def run_multihop_tasks(dria: Dria, file_chunks):
singleton = MultiHopQuestion()
executor = ParallelSingletonExecutor(dria, singleton)
executor.set_models(
[
Model.QWEN2_5_72B_OR,
Model.GEMINI_15_PRO,
Model.GPT4O,
Model.ANTHROPIC_SONNET_3_5_OR,
Model.ANTHROPIC_HAIKU_3_5_OR,
]
)
executor.load_instructions(
[{"chunks": random.sample(file_chunks, 3)} for _ in range(10)]
)
return await executor.run()
That's it for generating synthetic data for evaluation.
Evaluation¶
To evaluate the RAG pipeline, we need to compare the generated questions and answers with the ground truth.
Evaluator Class¶
The Evaluator class uses the instructor library to interact with OpenAI's API for chat completions to evaluate the generated questions.
We'll use the EvaluationResult pydantic model to structure the data for validation and processing.
import instructor
from pydantic import BaseModel, Field
from openai import OpenAI
class EvaluationResult(BaseModel):
evaluation: str = Field(...)
reasoning: str = Field(...)
class Evaluator:
def __init__(self):
self.client = instructor.from_openai(OpenAI())
def evaluate(
self, question: str, prediction: str, ground_truth: str
) -> EvaluationResult:
return self.client.chat.completions.create(
model="gpt-4o",
temperature=0,
response_model=EvaluationResult,
messages=[
{
"role": "system",
"content": "You are a world class judge to evaluate predicted answers to given question.",
},
{"role": "user", "content": f"Question: {question}"},
{"role": "user", "content": f"Prediction: {prediction}"},
{"role": "user", "content": f"Ground truth: {ground_truth}"},
],
)
Running the Evaluation pipeline¶
We can now evaluate the generated questions and answers using the Evaluator class.
def main():
# Load dataset
dataset = load_dataset("m-ric/huggingface_doc")
eval_chunks = dataset["train"].select(range(int(0.01 * len(dataset["train"]))))
eval_chunks = [chunk["text"] for chunk in eval_chunks]
# Create synthetic evaluation data using %1 of the dataset
dria = Dria(rpc_token=os.environ["DRIA_RPC_TOKEN"])
qa_eval = asyncio.run(run_qa_pipeline(dria, eval_chunks))
multihop_eval = asyncio.run(run_multihop_tasks(dria, eval_chunks))
# Initialize RAG
all_chunks = dataset["train"]
all_chunks = [chunk["text"] for chunk in all_chunks]
rag = RAG(all_chunks)
answers = {
"qa": [],
"1-hop": [],
"2-hop": [],
"3-hop": []
}
evaluate = Evaluator()
# Answer QA data
for pair in tqdm(qa_eval, desc="Answering QA"):
answer = rag.answer(pair["question"])
print("**** ", answer)
answers["qa"].append(
{
"prediction": answer.get_answer(),
"answer": pair["answer"],
"type": "simple",
"question": pair["question"],
}
)
# Answer multi-hop QA data
for pair in tqdm(multihop_eval, desc="Answering multi-hop QA"):
for hop_type in ["1-hop", "2-hop", "3-hop"]:
answer = rag.answer(pair[hop_type])
answers[hop_type].append(
{
"prediction": answer.get_answer(),
"answer": pair["answer"],
"type": hop_type,
"question": pair[hop_type],
}
)
# Evaluate all answers
for k, v in answers.items():
evaluated_answers = []
for answer in tqdm(v, desc="Evaluating answers"):
result = evaluate.evaluate(
answer["question"],
answer["prediction"],
answer["answer"],
)
evaluated_answers.append(
{
"question": answer["question"],
"answer": answer["answer"],
"prediction": answer["prediction"],
"evaluation": result.evaluation.lower(),
"reasoning": result.reasoning,
}
)
accuracy = calculate_accuracy(evaluated_answers)
print(f"********** {k} accuracy")
print(f"Total: {accuracy.total}")
print(f"Correct: {accuracy.correct} ({accuracy.correct_percentage}%)")
print(
f"Partially correct: {accuracy.partially_correct} ({accuracy.partially_correct_percentage}%)"
)
print(f"Incorrect: {accuracy.incorrect} ({accuracy.incorrect_percentage}%)")
print("**********")
with open(f"evaluated_answers_{k}.json", "w") as f:
f.write(json.dumps(evaluated_answers, indent=2))
Indexing, synthetic data generation, and evaluation steps took around 15minutes on a A10G.¶
Outputs may vary based on the sampled data and the RAG pipeline implementation. Expected output format:
...
Evaluating answers: 100%|██████████████████████████████████████████████████████████████████████████████████████████████████████████████| 39/39 [01:55<00:00, 2.97s/it]
********** qa accuracy
Total: 39
Correct: 16 (41.02564102564102%)
Partially correct: 7 (17.94871794871795%)
Incorrect: 9 (23.076923076923077%)
**********
Evaluating answers: 100%|██████████████████████████████████████████████████████████████████████████████████████████████████████████████| 18/18 [00:36<00:00, 2.05s/it]
********** 1-hop accuracy
Total: 18
Correct: 8 (44.44444444444444%)
Partially correct: 1 (5.555555555555555%)
Incorrect: 9 (50.0%)
**********
Evaluating answers: 100%|██████████████████████████████████████████████████████████████████████████████████████████████████████████████| 18/18 [00:30<00:00, 1.71s/it]
********** 2-hop accuracy
Total: 18
Correct: 12 (66.66666666666666%)
Partially correct: 0 (0.0%)
Incorrect: 6 (33.33333333333333%)
**********
Evaluating answers: 100%|██████████████████████████████████████████████████████████████████████████████████████████████████████████████| 18/18 [00:34<00:00, 1.91s/it]
********** 3-hop accuracy
Total: 18
Correct: 7 (38.88888888888889%)
Partially correct: 1 (5.555555555555555%)
Incorrect: 10 (55.55555555555556%)
**********
There you have it!
A complete guide to evaluating RAG systems with synthetic data. Please note we're using a RAG and synthetic data for demonstration purposes. Different RAG implementations and real-world data may yield different results.
Code¶
Complete script for the RAG pipeline can be found in SDK examples.