Unlocking the Power of AI Text Generation with Retrieval Augmented Generation (RAG)

Yadnyesh Gosavi
3 min readFeb 13, 2024

In the ever-evolving landscape of artificial intelligence (AI), breakthroughs continue to reshape the capabilities of NLP (Natural Language Processing). One such innovation that has captured the imagination of researchers, practitioners, and enthusiasts alike is Retrieval Augmented Generation (RAG). This advanced technique represents a significant leap forward in AI text generation, seamlessly combining the strengths of information retrieval and text creation. In this comprehensive guide, we’ll explore the intricacies of RAG, its applications across diverse domains, potential challenges, and best practices for implementation.

Understanding Retrieval Augmented Generation (RAG)

At its core, Retrieval Augmented Generation (RAG) represents a paradigm shift in AI text generation. Unlike traditional approaches that rely solely on generative models, RAG integrates two key components: retrieval models and generative models. Retrieval models act as intelligent “librarians,” sifting through vast repositories of data to fetch relevant information, while generative models serve as creative “writers,” synthesizing this information into coherent and contextually rich text. Application of RAG- Question-Answering Systems, Text Summarization, Content Generation,

  1. Retrieval Models:
  • Retrieval models are responsible for fetching relevant information from a large dataset or knowledge base in response to a given query.
  • These models utilize algorithms to search through the dataset and identify documents or passages that contain relevant information.
  • Common techniques for retrieval include vector embeddings, document indexing, and algorithms like BM25 and TF-IDF.
  1. Generative Models:
  • Generative models, on the other hand, are responsible for synthesizing coherent and contextually rich text based on the retrieved information.
  • These models typically leverage large language models (LLMs) like GPT and BERT to generate text.
  • Generative models can understand the context of a query and produce grammatically correct and semantically meaningful responses.

Now, let’s walk through a step-by-step implementation of RAG:

Step 1: Initialize Tokenizer and Language Model

from transformers import BertTokenizer, BertForMaskedLM


tokenizer = BertTokenizer.from_pretrained('bert-base-uncased')

model = BertForMaskedLM.from_pretrained('bert-base-uncased')
  • Here, we initialize a tokenizer and a pre-trained language model. We’re using BERT for this example, but you can use any other appropriate model.

Step 2: Define Retrieval Function

def retrieve_information(query, knowledge_base):
# Dummy function to retrieve relevant information from the knowledge base
# In a real-world scenario, you would implement actual retrieval logic here
relevant_info = knowledge_base.get(query, "No relevant information found.")
return relevant_info
  • This function simulates retrieving relevant information from a knowledge base based on the user’s query.

Step 3: Define Generation Function

def generate_response(query, knowledge_base):
# Retrieve relevant information based on the query
relevant_info = retrieve_information(query, knowledge_base)

# Generate response using the language model
masked_query = query.replace("[MASK]", tokenizer.mask_token)
tokenized_query = tokenizer.encode(masked_query, return_tensors="pt")
logits = model(tokenized_query)[0]
predicted_token_id = torch.argmax(logits, dim=-1)[0, -1].item()
predicted_token = tokenizer.decode(predicted_token_id)

return predicted_token
  • This function generates a response based on the user’s query by filling in a masked token in the query using the language model.

Step 4: Example Interaction

# Dummy knowledge base
knowledge_base = {
"What is the capital of France?": "The capital of France is Paris.",
"Who wrote 'Romeo and Juliet'?": "William Shakespeare wrote 'Romeo and Juliet'."
}
# User query
user_query = "Who wrote [MASK] and Juliet?"

# Generate response
response = generate_response(user_query, knowledge_base)
print("Response:", response)
  • In this example, I provide a dummy knowledge base and a user query with a masked token.
  • The generate_response function retrieves relevant information from the knowledge base and generates a response by filling in the masked token using the language model.
  • Finally, the response is printed to the console.

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