Why Do AIs Make Things Up? Meet RAG, the Technology Teaching Them the Truth.

by 🧑‍🚀 Lee Xuan Zern on Fri Sep 19 2025

An abstract illustration of a digital brain surrounded by scattered, incorrect information, with a glowing pathway connecting it to an organized, truthful library of data, representing RAG.

Intorduction

Ever asked a chatbot a simple question and gotten a bizarrely confident, yet completely wrong, answer? Maybe you asked for a recipe and it invented an ingredient, or you inquired about a historical event and it confidently stated it happened in the wrong century. If so, you’re not alone. You’ve just witnessed an AI “hallucination.”

These moments are strange because the AI sounds so sure of itself, but the information can be pure fiction. It’s a fundamental flaw that leaves many of us wondering if these powerful tools can ever be truly reliable. But what if there was a way to teach an AI not just to remember, but to check its facts first?

This is where our story begins. While the problem is common, a fascinating technology is emerging as the hero. This post will tell the story of Retrieval-Augmented Generation (RAG)—the groundbreaking approach designed to make AI more honest by giving it a way to find the truth before it ever gives you an answer.

The Problem: An AI with a Perfect Memory but No Library

To understand why an AI would just make things up, it helps to think of it not as a supercomputer, but as a brilliant student. This student has read almost every book, article, and website published up to a certain point in time. Their memory is flawless, but there’s a catch: they are now locked in a room and must answer every question based only on what they’ve already memorized.

The ‘Closed-Book Exam’ Dilemma

This is essentially how a standard Large Language Model (LLM) works. It’s taking a perpetual “closed-book exam.” Its knowledge is vast, but it’s frozen in time. For instance, a model trained on data up to 2023 wouldn’t know the winner of the 2024 World Series or that the current time here in Petaling Jaya is 4:52 PM. When faced with a question it can’t answer from its memory—or a topic where its knowledge is thin—it doesn’t say “I don’t know.” Instead, it improvises. It uses the patterns it learned during its training to create an answer that looks right, even if it’s factually incorrect. This is the source of hallucinations.

The Danger of Confident Mistakes

For a student, a wrong answer on a test might mean a lower grade. But for an AI, a confidently wrong answer can be a serious problem. It could provide incorrect legal information, faulty code that breaks a system, or misleading details about a company’s product. Every time an AI hallucinates, it erodes our trust. After all, what good is a tool if you can’t rely on the answers it gives you? This is the fundamental challenge that needed a solution.

The Hero Arrives: What is Retrieval-Augmented Generation (RAG)?

What if we could give that brilliant student in the locked room a key? Not a key to escape, but a key to a library filled with up-to-date, factual books. What if, instead of relying only on memory, they could quickly find the right information before answering any question? The answers would become dramatically more accurate and trustworthy. This is exactly what Retrieval-Augmented Generation (RAG) does for AI.

Giving the AI a Library Card

RAG isn’t about making the AI’s memory bigger; it’s about giving it a new skill: the ability to research. In simple terms, RAG is a system that connects a creative Large Language Model (LLM) to an authoritative knowledge source. This source could be a curated database, a company’s internal product manuals, or even the live internet. It’s like giving the AI a library card to access a collection of books you trust.

The ‘Open-Book Exam’ Analogy

If a standard AI is taking a “closed-book exam,” then an AI powered by RAG is taking an “open-book exam.” Instead of guessing or improvising when faced with a tricky question, the RAG-powered AI does something smarter. First, it “retrieves” the most relevant, up-to-date information from its connected library. Then, it uses that freshly gathered information to “augment” (or enhance) its understanding. Only after this fact-checking step does it “generate” the final answer. This simple but powerful process is the key to teaching AI the truth.

The Secret to the Search: A Quick Technical Detour

Our story about the AI librarian is a great way to understand the goal, but how does the librarian actually find the right book in a library of millions in less than a second? It doesn’t read the titles; it understands the meaning. This is accomplished through a concept called vector embeddings and a clever end-to-end process.

Part 1: Creating the ‘Map of Meaning’ with Vector Embeddings

Before anyone asks a question, the system does its homework. It reads every single document in its knowledge base, breaking it down into manageable chunks, like paragraphs. For each chunk, it creates a vector embedding. Think of an embedding as a set of coordinates, like a GPS location. But instead of mapping a physical location, it maps the meaning of the text. This process turns words and sentences into a list of numbers (a vector), placing them on a vast, multi-dimensional “map of meaning” where distance equals a difference in meaning. This map is stored in a special, high-speed system called a vector database. This is the librarian’s master catalog.

Part 2: The End-to-End Process in Action

Now, when you ask a question, the full RAG system follows these precise steps:

  1. Encode the Question: Your question is also converted into a vector embedding, placing it as a new point on that same “map of meaning.”
  2. Find the Neighbors (Retrieval): The system instantly finds the existing document points that are closest to your question’s point. This is the technical magic behind “retrieval.”
  3. Combine and Brief (Augmentation): The system grabs the original text of those top-matching chunks and combines it with your question to create a new, super-detailed prompt.
  4. Create the Answer (Generation): This rich prompt is finally sent to the LLM, which can now compose a precise and truthful answer, directly grounded in the source material.

A World with More Honest AI: Why RAG Matters to You

Understanding the story of RAG and its clever mechanics is interesting, but the real excitement comes from how it changes the way we interact with AI every day.

Trustworthy Answers

With RAG, a customer service chatbot is connected directly to the latest product manuals. When you ask about the battery life of a specific device, you get a number pulled from the official source, not a confident-sounding estimate. This transforms AI from a novelty into a truly dependable tool.

Always Up-to-Date Information

Standard AI models are perpetually stuck in the past. RAG shatters this limitation. By connecting to live data sources, an AI with RAG can be as current as the morning’s news. For instance, it can know that today is Thursday, September 18th, 2025, something a standard model couldn’t.

Citing Its Sources

Perhaps the biggest leap forward for trust is transparency. Many RAG systems are designed to show their work, providing footnotes or links directly to the source documents they referenced. This means you don’t have to blindly trust the AI; you can verify the information for yourself.

Conclusion

The story of AI is still being written, but Retrieval-Augmented Generation is a pivotal chapter. We started with a brilliant but flawed protagonist—an AI that relied on a frozen, imperfect memory. By introducing RAG, we gave our hero a library card and the ability to take an “open-book exam.” By grounding its powerful language skills in verifiable facts, we’ve created a tool that is not only smarter but also more honest. The next time you get a surprisingly accurate and helpful answer from an AI, you’ll know the secret hero working behind the scenes.

Call to Action:

What’s the most useful (or funniest) AI answer you’ve ever received? Share it in the comments below!

Tagged: RAGAILLMHallucinationTruthfulness

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