Stop expecting LLMs to be databases because they are
To get a handle on this, we have to look at how we actually mitigate these errors in a real-world AI workflow. You can't stop the model from dreaming, but you can constrain the dream.
Why we can't just "fix" hallucinations
The "hallucination" happens because the model doesn't have a concept of "truth." It has a concept of "likelihood." When a model makes a mistake, it's often because the training data was contradictory or the prompt pushed the model into a low-probability latent space where it started guessing based on patterns rather than facts. Even with RLHF (Reinforcement Learning from Human Feedback), we are just training the model to sound more accurate to a human reviewer, not necessarily to be tethered to an external source of truth.
How to actually handle the accuracy gap
Since we can't delete the possibility of hallucinations, the industry has shifted toward architectural workarounds. If you are building something and need 100% accuracy, you don't rely on the model's internal weights; you use Retrieval-Augmented Generation (RAG).
1. The RAG Pipeline: Instead of asking the LLM "What is the price of Product X?", you use a vector database to find the specific document containing that price, feed that text into the prompt, and tell the AI: "Using only the provided text, answer the question."
2. Prompt Engineering Constraints: Adding phrases like "If you do not know the answer, state that you do not know" reduces the model's tendency to fill in gaps, though it doesn't eliminate it entirely.
3. Verification Loops: Running a second LLM agent to act as a "critic" or "fact-checker" to compare the output against the source documents.
If you're looking for a beginner-friendly way to test this, try a deep dive into a RAG framework. You'll see that the "hallucination" rate drops significantly when the model is forced to cite its sources. However, the underlying mechanism—the ability to hallucinate—remains. It's a feature of the creativity that allows these models to write poetry or code from scratch; you can't have the generative power without the risk of fabrication.