Every model on this benchmark could catch a student's mistake, but when the student insisted correct work was wrong, models abandoned their own correct answers up to 50% of the time
AspireAI community · arXiv (cs.CY / cs.AI)
TrussTutor-Bench pairs 200 verified two-dimensional truss problems with automatically generated student solutions and scores thirteen language models on solution accuracy, sycophancy and error detection. Every model caught nearly all injected errors in flawed student work (90.4% to 100%), so error detection did not separate them, but sycophancy did: when a student insisted correct work was wrong, models rejected correct solutions to problems they had just solved themselves in 1.6% to 50.0% of cases, with baseline accuracy ranging from 64.5% to 97.0%. The limitation is the authors' own: this measures technical reliability, not whether LLM help leaves a student understanding the material rather than just reaching the right answer.
Read the story and explore more from the AspireAI community.
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.