Reading companion
Glossary & sources
Definitions, source status, assumptions, and any optional marked additions behind the field guide.
A small vocabulary
- Policy
- A conditional distribution over the next token in this guide.
- Trajectory
- A generated response sequence; its prefixes provide the states evaluated during tokenwise distillation.
- Prefix
- The prompt plus response tokens generated before the current position.
- On-policy
- Here, the response occurrence was sampled from the student behavior policy used for collection.
- Behavior policy
- The policy that generated the collected response; it may differ from the current trainable parameters later.
- Teacher
- The model supplying supervision at the selected prefix; teacher probability is not automatically correctness.
- Forward KL
- D_KL(teacher || student) at one held-fixed prefix in this notation.
- Reverse KL
- D_KL(student || teacher) at one held-fixed prefix in this notation.
- Nat
- The information unit produced by natural logarithms.
- Stop-gradient
- An estimator choice that treats a dependency as fixed during differentiation; here it applies to the sampled trajectory.
Primary sources and status
SRC-GKD-ICLR-2024· Peer-reviewed · ICLR 2024 official recordOn-Policy Distillation of Language Models: Learning from Self-Generated Mistakes
Canonical publication anchor for GKD. It does not turn this toy into model evidence.
SRC-GKD-ARXIV· Author manuscript v3 · 2024-01-17 · accepted at ICLR 2024Agarwal et al. author manuscript, arXiv:2306.13649v3
Navigable equations, Algorithm 1, source mixture, divergence choices, and stop-gradient statement.
SRC-MINILLM-ICLR-2024· Peer-reviewed · ICLR 2024 official recordMiniLLM: Knowledge Distillation of Large Language Models
Sequence-distribution reverse KL and its policy-gradient decomposition; distinct from the canonical local toy.
SRC-OPD-RETHINKING-2026· Recent preprint evidence · arXiv 2026 · not peer reviewedRethinking On-Policy Distillation of Large Language Models
Preprint evidence used only to mark current feedback-granularity questions; no empirical conclusion is imported into the guide.
SRC-SEQKD-EMNLP-2016· Peer-reviewed · EMNLP 2016Sequence-Level Knowledge Distillation
Fixed teacher beam outputs used as hard sequence targets.
SRC-IMITKD-EMNLP-2020· Peer-reviewed · EMNLP 2020Autoregressive Knowledge Distillation through Imitation Learning
Sequence-source mixture, oracle supervision, schedule, and sample-pooling boundaries.
What this guide does not establish
The probabilities in OPD-TOY-001 are invented teaching inputs. They are not a trained language model, a benchmark, or evidence that one method wins. No learner study or controlled learning outcome is claimed. Cross-tokenizer alignment, EOS inclusion, production length weighting, behavior-policy lag, and teacher correctness remain implementation questions beyond the fixture.