arXiv Machine Learning

CSD: Common-Support Distillation for Cross-Tokenizer Knowledge Transfer

The paper introduces Common‑Support Distillation (CSD), a logits‑based framework for transferring knowledge across different tokenizers by constructing a shared support between teacher and student distributions. CSD handles both one‑to‑one alignments using explicit common‑token pairs and other alignments by creating a virtual support via the autoregressive chain rule, while a residual event ensures normalization. Experiments on Llama‑3.2‑1B, Gemma3‑1B‑PT, Qwen, and Phi models show that CSD consistently outperforms existing cross‑tokenizer methods, achieving up to 1.8‑point gains over the best alternative and surpassing both continued pretraining and same‑tokenizer distillation.

arXiv Machine Learning
Oct 12

CAST: Credit Alignment for Cross-Tokenizer On-Policy Distillation

CAST (Chunk-aware credit Assignment with Selective Token Anchoring) is a new framework for cross-tokenizer on-policy distillation that tackles two key problems: credit alignment and unaligned token positions. It redistributes chunk-level advantage signals across student tokens using predictive uncertainty and teacher-signal smoothness, while anchoring unaligned tokens to the initial policy via a KL penalty. Experiments on six mathematics, science, and code benchmarks show that CAST improves average performance over the strongest baseline by up to 2.45 points in cross-tokenizer transfer scenarios.

By Jingru Yang, Jinhang Wu, Minjing Shi, Shengfeng He, Xuyan Li, Man Tan, Biye Li
arXiv AI
Jul 23

When Does Knowledge Distillation Hurt? Reliability-Aware Distillation for Low-Resource Language Summarization

arXiv:2607. 19956v1 Announce Type: cross Abstract: Knowledge distillation (KD) is a standard approach for compressing sequence-to-sequence models, but its per-sample effects are rarely examined.

By Dipto Sumit, Ankan Kumar Roy Srizon, Sadia Khair Rodela, Atia Haque Asha, Mourchona Afrin, Niloy Farhan, Farig Sadeque
arXiv AI
Jun 9

Trajectory-Refined Distillation

arXiv:2606. 08432v1 Announce Type: new Abstract: On-policy distillation (OPD) has become a central post-training tool for large language models (LLMs), providing dense per-token teacher supervision along the student's own rollouts.

By Li Jiang, Haoran Xu, Yichuan Ding, Amy Zhang
arXiv Machine Learning
Sep 4

ALRA: Adaptive Local Relational Alignment for Logit-Based Pre-training Distillation of Autoregressive Language Models

The paper introduces Adaptive Local Relational Alignment (ALRA), a logit‑based knowledge distillation method for autoregressive language models that combines student‑generated token proposals with teacher guidance at each prediction position. ALRA dynamically selects the number of candidate tokens based on the teacher’s probability spread, uses Adaptive Local Divergence to match both mass and relative token distributions, and applies Student‑Weighted Pairwise Relational Alignment to focus on high‑probability token pairs. Experiments on The Pile show that 200M‑ and 500M‑parameter students trained with ALRA outperform the best baseline by roughly 1 percentage point and surpass pre‑training without distillation by over 2 percentage points on nine zero‑shot benchmarks.

By Quang Hoang Trung, Quang Huu Hieu, Nguyen Van Hoang Phuc, Vo Nguyen Le Duy
arXiv Computation and Language
Sep 1

ACTD: Anchor-Based Cross-Tokenizer Distillation with Residual Regularization

The paper introduces ACTD, an Anchor-Based Cross-Tokenizer Distillation method that aligns vocabularies and sequences to transfer reasoning capabilities from large language models to smaller students. It uses a novel anchor loss with residual regularization to reduce alignment noise and extends the approach to multiple teachers. Experiments on five reasoning benchmarks with three teachers show state‑of‑the‑art results, with the multi‑teacher variant outperforming existing baselines.

By Huiyi Zhang, Zijian Li, Xiaocheng Feng, Weitao Ma, Xiaoliang Yang, Yichong Huang, Bing Qin