• Justin@lemmy.jlh.name
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    1 month ago

    I thought confidence levels were for image recognition? How do confidence levels work for transformer LLMs?

    • jarfil@beehaw.org
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      1 month ago

      LLMs generate output one token at a time. Each token comes with a confidence level by the model, about whether it’s the only possible token to continue the sequence. A model is only 100% confident in its output, if it reproduces a training text verbatim. With any temperature above 0, they veer off the 100% confidence path, which lets them leverage the concept association they came up with during training, makes their output more useful.

      For every generated text, you could get a confidence heat map, then ask the model to refine sections that don’t meet a desired level of confidence. Especially the parts where a model makes stuff up, or hallucinates, are likely token sequences with much lower confidence than the rest.

      Running a model several times, focusing on the sections with lower confidence, getting additional data from other sources like the internet, or some niche expert system, could eliminate many of the nonsense sections… and I have a reasonably suspicion that Google’s Gemini does exactly that, refining each output with 4 additional iterations, instead of blindly spitting out the first one.

      • Justin@lemmy.jlh.name
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        1 month ago

        I guess that makes sense, but I wonder if it would be hard to get clean data out of the per-token confidence values. The LLM could be hallucinating, or it could just be generating bad grammar. It seems like it’s hard enough already to get LLMs to distinguish between “killing processes” and murder, but maybe there could be some novel training and inference techniques that come up.