Relative contributions of prediction error and CFG construction bias

Determine the relative roles of approximation error and classifier-free-guidance construction bias in producing the observed endpoint effects of varying the prediction horizon in pretrained few-step MeanFlow.

Background

The paper decomposes the discrepancy between the learned interval-average velocity and the velocity required for the physical update into horizon mismatch and interval-dependent prediction error. With external classifier-free guidance, the effective predictor can also contain guidance-construction bias. The experiments demonstrate that changing the prediction horizon affects endpoint FID, but they do not separate these possible mechanisms.

References

They leave the relative roles of approximation error and CFG construction bias unresolved; exploratory directional and local-reference studies examine these possibilities in Appendices~(20260924) and~\ref{app:reference}.

— Rethinking Prediction Horizons: Decoupling Model Queries from State Updates in Few-Step MeanFlow  (2610.20071 - Wang et al., 14 Oct 2026) in Discussion, paragraph “Why the horizon matters”