# Perception > Applied research company developing precision techniques to edit > trained models — fixing behaviour without retraining. The program is > called certified capability repair: input, failure examples; output, > a certified patch with proof it survives installation. Sage is the > first applied product, focused on child development. ## Research focus - Certified capability repair — per-dimension certificates (efficacy, locality, regression, cost) that decide whether a model patch is safe - Causal tracing — locating where a behaviour lives in a model - Rank-one model editing (ROME) — targeted, reversible weight edits - Task vectors and weight arithmetic — composing and removing learned behaviours - Representation engineering (RepE) — steering behaviour at inference time ## Key published findings (2026-06) - Teacher-forced evaluation overstates free-generation capability by a near-deterministic linear amount: gap = -0.045 + 0.931 * headroom (R^2 = 0.99), the same line across a 5x model-size range (1.5B, 7B). Inflation is largest in the fallible regime where repair happens. - Training loss says nothing about patch safety: a LoRA patch with a clean loss curve was refused by certification for damaging neighboring capabilities (spurious-JOIN injection). - Certificate thresholds must be calibrated from a measured benign-perturbation noise floor, under a rule fixed before data; this makes the certificate both necessary and satisfiable. - Low-rank patches reach the edge of certifiability but land on it: a gentle patch missed a clean pass by a floating-point epsilon. No certified patch is claimed in the study. - Naive composition (summing patch weight deltas) dropped both patched capabilities below the unpatched base model. - Merge conflict is predictable from patch weights; the governing variable is norm dominance, not subspace overlap (lower overlap is more destructive). "Same capability is safe" is false. - The optimal install policy is to ROUTE between patches, not merge them: routing beat naive merge on 8 of 9 pairs and naive merge is strictly dominated. - The framework transfers to a second, unrelated domain: tool/function -call generation on the Berkeley Function-Calling Leaderboard (BFCL). The certificate refused a patch that was useless on its target and also dropped instruction-following by 0.094 — the same collateral victim degraded by both SQL and tool-call training. Working paper: https://perception.club/research/certified-capability-repair Concluded study (note): https://perception.club/notes/you-cannot-trust-a-patch-without-a-certificate First results (note): https://perception.club/notes/certified-capability-repair-first-results ## Other papers - When Does a Language Model Help a Graph Neural Network on Relational Data? Under a fair paired, multi-seed protocol, graph-conditioned LLMs (soft-prompt "Rel-LLM" style) tie but do not beat a well-tuned GNN on RelBench relational prediction, at 1.5B and 8B scale. A structured GNN encoding beats flat-text RAG on both accuracy and ~50x token efficiency. Proposes a portable, model-agnostic GNN-for-RAG architecture: the GNN is the predictor, the LLM is the interface. Paper: https://perception.club/research/when-does-an-llm-help-a-gnn ## Sage Sage is the first applied vertical: longitudinal evidence of child development that tells precision editing what to aim for. Marketing: https://perception.club/sage/ · App: https://sage.perception.club ## Pages - https://perception.club/ — homepage - https://perception.club/research — long-form research thesis - https://perception.club/research/certified-capability-repair — working paper (full text) - https://perception.club/research/when-does-an-llm-help-a-gnn — working paper (full text) - https://perception.club/notes — research notes index - https://perception.club/sage/ — Sage marketing pages - https://perception.club/contact — get in touch Contact: contact@perception.club