aspireai.
PUBLIC EDITION

One 9B model reranked its own passages from a shared prefill, beating a separate cross-encoder at 0.741 nDCG@10 on SciFact

AspireAI community · arXiv (cs.CL)
Retrieval-augmented generation usually runs two models: one reranks passages, another answers from them. Glance removes the second model by giving the generator a lightweight decision adapter and pointer head that scores candidate passages from a shared prefill, with short relevance probes branching off the cached context instead of prefilling each query-passage pair separately. One resident 9B backbone then handles generation, decisions and reranking, adding roughly 0.1 GiB of memory per decision skill. After 39 minutes of MS MARCO fine-tuning on one B200, Glance reached nDCG@10 of 0.741 on SciFact and 0.345 on NFCorpus, against 0.721 and 0.326 for bge-reranker-v2-m3, and on 300 HotpotQA questions its selected context improved answer F1 by 0.045 over cross-encoder-selected context under the same base generator, paired bootstrap 95 percent CI 0.014 to 0.076. Reranking quality kept improving up to 200 candidates scored from one prefill, where it exceeded the cross-encoder by 0.058 nDCG@10. The authors are clear about the scope: two retrieval datasets, one QA dataset and one backbone family, with adapters and code released on Hugging Face.
Read the story and explore more from the AspireAI community.
Discover more stories
Stay curious.
THE BIG PICTURE
A FRESH PERSPECTIVE
Research
One distance function matched sparse-autoencoder features across layers and compressed feature circuits into supernodes
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.
Swipe into something new
01 / 1729
The conversation continues
Explore Builds — projects by Kiran Adimatyam ↗
A fresh perspective changes everything.
ASPIREAI — STAY CURIOUS.