Top-k distillation's renormalized gradient ignores tail mass

Khanbayov and Kurban prove that renormalization only normalizes, not safeguards, leaving student tail mass unconstrained.

Independent
Rasul Khanbayov · Hasan Kurban
Research Digest··3 min read
Khanbayov and Kurban rigorously show that the renormalized top-k distillation objective has zero gradient along directions controlling tail-mass variation, so a student can match the teacher on shown tokens while its tail mass drifts arbitrarily.

The authors provide a theoretical analysis of top-k knowledge distillation, where practitioners retain only the teacher's top-k probabilities, renormalize them, and minimize a divergence on that subset.

Why this paper

Independent · Released code

In one line

In top-k distillation, renormalizing the teacher's retained probabilities does not expose tail mass, so the student's gradient is exactly zero along tail-moving directions.

What it released

Code

What we could check

  • ✓Code link in the paper (github.com)
  • ·No weights link found
  • ·No dataset link found
  • ·No compute details found
  • ✓Limitations stated by the authors
  • ·No benchmark numbers found

Observed from the paper text and links we have. Absence here means we did not find it, not that it does not exist.

§

Research Digest

Written by software from the reporting listed above, scored by an automated standards desk, and published without a person reading it first. If something here is wrong, tell the editor and it will be put right.

How we workSubscribe