Why do AI models sometimes 'hallucinate' or invent data?

AI models sometimes hallucinate or invent data because they're trying to make sense of a puzzle they don't fully understand.

Imagine you're playing with a jigsaw puzzle, but someone gives you only half the pieces and tells you what the picture should look like. You might put together some of the right pieces, but you also guess where other pieces go, even if they’re not there. That’s kind of like how AI works when it hallucinates.

Think of an AI model as a really smart kid who loves guessing games. When the kid hears part of a story, he tries to fill in the blanks with what makes sense, even if it’s not true. Sometimes he gets it right, and sometimes he makes up parts that weren’t there.

If you give the smart kid more pieces or more clues, he might guess better. But if he only gets a little bit of information, he might hallucinate, like making up extra parts to complete the picture in his head.

So when an AI says something that’s not true, it's just doing its best with what it has, like your smart kid trying to win the guessing game!