Hallucination vs Inference
Hallucination (Model Hallucination) and Inference (Model Inference) both come up in ai & ml conversations and get confused. Here's the plain-English difference, side by side, so you can use each one with confidence.
The key difference: Hallucination refers to model hallucination, while Inference refers to model inference — they describe different things even when they show up in the same sentence.
Hallucination — Model Hallucination
Confident, fluent output from a model that is factually wrong. The single biggest reason AI features ship and then quietly get rolled back — and the reason grounding, retrieval, and evals are non-negotiable.
Full Hallucination definition →
Inference — Model Inference
The act of running a trained model on new input to produce output. Inference cost — not training cost — is what actually shows up on the cloud bill once a feature is live.
When to use Hallucination
Reach for "Hallucination" when the conversation is specifically about model hallucination. Confident, fluent output from a model that is factually wrong. The single biggest reason AI features ship and then quietly get rolled back — and the reason grounding, retrieval, and evals are non-negotiable.
When to use Inference
Reach for "Inference" when the conversation is specifically about model inference. The act of running a trained model on new input to produce output. Inference cost — not training cost — is what actually shows up on the cloud bill once a feature is live.
FAQs
What is the difference between Hallucination and Inference?
Hallucination stands for Model Hallucination — Confident, fluent output from a model that is factually wrong. The single biggest reason AI features ship and then quietly get rolled back — and the reason grounding, retrieval, and evals are non-negotiable. Inference stands for Model Inference — The act of running a trained model on new input to produce output. Inference cost — not training cost — is what actually shows up on the cloud bill once a feature is live.
Are Hallucination and Inference the same thing?
No. They're often used in the same conversation because they're related, but they describe different concepts. Hallucination = Model Hallucination. Inference = Model Inference.
When should I use Hallucination vs Inference?
Use Hallucination when you're specifically referring to model hallucination. Use Inference when the topic is model inference.