Surprisal Theory is Tautological (without Rational Grounding)
Surprisal theory claims that processing difficulty is determined by a language model's surprisal, but this is unfalsifiable because any difficulty pattern can be explained by constructing a specific language model to fit it. The paper argues this requires restricting the set of possible models (Q) based on cognitive principles rather than just empirical data, suggesting a need for rational grounding to make the theory testable.