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Before this experiment I tried to run KLD on various context lengths to see a quantization-dependent deterioration.

On wikitext2 there was no difference. I concluded these have no long-term dependency and I should use Linux kernel. Still, the same.

So yes, KLD depends on the dataset. Still, it does not measure what any e2e test does.

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Yeah, makes sense; e2e is different and valuable, KLD is not a replacement.

As for KLD, have you tried it on something which is even closer to e2e task, like agentic traces from https://huggingface.co/datasets/nvidia/Nemotron-Cascade-2-SF... or similar datasets?

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Nope.

If you would like to do so, it is easy (and orders of magnitude cheaper) than running benchmarks.

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> A common issue is that it's rarely mentioned on which dataset KL-divergence is computed. It seems the most common dataset is wikitext

Thank you for calling this out. Using Wikipedia snippets for these is a terrible choice. I did a bunch of KL and other stats with the five Gemma 4 models, and the results were non-obvious. Anthropomorphizing:

Gemma 4 31B: "I guess we'll pretend I said this, but it's not me." (Baseline for stats)

Gemma 4 26B: "Dude, I'm certain I wouldn't have said this." (Bad KL)

Gemma 4 12B: "Umm, Me either!" (Similarly Bad KL)

Gemma 4 E4B: "I might say almost anything, this is fine." (Much better KL!!!)

Gemma 4 E2B: "I'm basically a toy. Let's play a game!" (Same KL as E4B)

Anyway, for comparing quantizations, it seems like the largest precision version should be given a one-shot prompt, and the result from that should be used as the corpus for the quantized versions.

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> Anyway, for comparing quantizations, it seems like the largest precision version should be given a one-shot prompt, and the result from that should be used as the corpus for the quantized versions.

Way better than wikitext-- but tells you nothing about errors tending to compound or cancel out.

Like say a test shows that only one token in a 10,000 token test would be different. Sounds very close, ship it!-- but what if trajectories with that single different token guarantees failure because it sets in motion a cascade of differences that ultimately result in a final distribution that doesn't include the solution?

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