Research & Papers

The loss curve said tie. The judges said otherwise. Seeking replication for an early LLM training result [R]

One GPU researcher's new loss functions show 60% human preference in LLM outputs

Deep Dive

An independent researcher has introduced two novel loss-shaping functions for LLM training that show a 59.9% human preference rate over standard cross-entropy training in blind evaluations. The functions—per-token gain and per-layer divergence scaling—were tested on two 1.2B-parameter models trained on identical data for 30,000 steps (3.9B tokens). The per-token gain function scales each token's loss by its surprise level: confident correct tokens get reduced weight while surprising tokens are amplified, preserving the overall gradient budget. The per-layer divergence scaling adjusts gradients per transformer block based on how much that block changed the representation during forward pass, amplifying actively-revising layers and attenuating settled ones.

The evaluation involved 42 blind judges (29 humans and 13 foundation models from 11 vendors) making 1,181 pairwise comparisons. The gain-trained model was preferred in 59.9% of 784 decisive comparisons (two-sided binomial p=2.80e-8). Humans and AI judges showed remarkable agreement: 60.5% vs 59.0% decisive preference, with 81.2% agreement on which prompts favored the new method. The result survived all sensitivity filters including excluding speed-clickers and tie-biased judges. Limitations include single seed testing at 1.2B parameters, training only 16.4% of Chinchilla-optimal tokens, and no separate ablation of the two functions. The researcher seeks an arXiv endorser for the cs.LG category.

Key Points
  • Two novel functions: per-token gain (scales loss by token surprise) and per-layer divergence scaling (amplifies active transformer layers)
  • 42 blind judges (29 humans + 13 AI models) preferred the new method 59.9% of the time (p=2.80e-8)
  • Results consistent across human and AI judges with 81.2% agreement on prompt-level preferences

Why It Matters

Could improve LLM training efficiency and output quality with minimal code changes, democratizing better AI