Neural scaling laws were predicting the wrong curve: a learned forecaster cut accuracy-prediction error 44%
AspireAI community · arXiv (NeurIPS 2026)
NeuNeu reframes scaling-law prediction as time-series extrapolation, feeding token-level validation loss together with the observed downstream accuracy trajectory into a neural network instead of fitting a fixed power-law form. Trained only on open-source checkpoints from Hugging Face, it reaches 1.99% mean absolute error predicting model accuracy across 66 downstream tasks, a 44% reduction against logistic scaling laws at 3.56% MAE, and generalises zero-shot to model families, architectures and parameter counts it never saw. The paper's own ablation attributes roughly 90% of the improvement to replacing the parametric form with a learned predictor rather than to the token-loss signal, and the gains are measured on accuracy trajectories rather than on loss.
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Two sparse-autoencoder analyses have resisted scaling: matching semantically similar features across layers, and compressing large feature circuits into interpretable supernodes. This paper argues both are the same underlying problem, estimating semantic distances between SAE features that sit on different activation manifolds. Its representation treats each feature not as a single decoder vector but as an activation-weighted distribution over the hidden states expressing it, projects those distributions into a shared reference space, and compares them with Wasserstein distance. The representation is proved invariant to activation rescaling and stable under perturbation, and recovers true matches under finite-sample margin conditions. Empirically it outperformed decoder-vector and LLM-based baselines and captured subtle functional distinctions between related features, and it compressed large feature circuits into interpretable supernodes automatically. The limitation is that this is interpretability tooling: the paper demonstrates better feature matching and circuit compression, not that downstream interpretability claims become more accurate.