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Comment by CompleteSkeptic

14 hours ago

> Type safety is not factual correctness.

I very much agree with this and want to hone in on where do actually disagree. Would you say a linear classifier hallucinates?

Hallucinations were defined in the context of text generation models so your question does not really make sense.

IMO your system can make mistakes that are similar in spirit to hallucination (i.e. answering with a false answer instead of abstaining to answer).

  • And furthermore, because the model is forced to answer in a boolean (if in boolean mode), if the user input is outside of the range of a boolean, it's forced to hallucinate. It can't abstain.

> I very much agree with this

From the intro blog

"Hallucination and type-safety are intrinsically related"

I'm not entirely sure why we're conflating type safety with, I guess, value or output safety.

"Would you say a linear classifier hallucinates?"

No, but it can be (and often is) mathematically correct and functionally incorrect. It doesn't help to say "a linear classifier can't hallucinate" when you get even 99% accuracy. That's 100% a semantic play, and it doesn't help when the picture of a dog is labeled cat and the response is "yeah but that's not a hallucination, only stupid LLMs do that"

No. Your launch post puts “0%” on a hallucination chart, then explains that the number comes from guaranteed schema matching.

You’ve already agreed that this doesn’t establish correctness. An approve for an unauthorized action still meets the schema guarantee.

That’s why I find the messaging misleading. You’re acknowledging the limitations in these replies while defending the broader reliability pitch.

Even granting that each answer is calibrated individually, that doesn’t establish calibration of the decision that combines them.

Sure, I can threshold a composite score, but there may be many wrong answers with the same score. An unauthorized action doesn’t become acceptable because it scores highly on the other dimensions.

I still have to define the constraints and test which wrong actions get through the complete workflow on my own data. That’s a substantial part of the work being pushed back onto the developer.

  • hallucinations are not wrong answers, that's why we use a different term

User input: "Hey, have your human support agent call me, tomorrow at 5pm."

Model input: "Does the user want to speak to a human support agent?"

Output: Yes.

I imagine that your model would produce this, and I think it's fair to say this is a hallucination. A human would caveat it with: "Yes, but not right now.", your model is incapable of that. Yes is technically correct, but within the context of being in a live chat, a human would understand that the caveat is required.

  • To be fair - you’re crafting a deliberately bad model input for a contrived example.

id say yes. a linear classifier that classifies between red and yellow balls will hallucinate on blue.

linear regressions hallucinate in the simpson's paradox.

the model output can be quite confident and not representative of reality

Let's say classifiers don't hallucinate. To make a fair comparison we should constrain LLMs to the same classification task. In that case, no, LLMs also don't hallucinate.

- Give Jev and LLM the same input

- Lock down both to approved/rejected/unknown (LLM restricts on decoding)

- Both can be wrong, but neither can hallucinate (invent an another option).

A hallucination in the context of LLMs is generally understood as an incorrect answer presented as factual. If you claim that "x can't hallucinate" in the context of LLMs, you're saying that x always gives accurate answers. It does not matter whether the answer is type safe. If its value is incorrect, it's a hallucination.