Reproducing J-Space Analysis to Examine Model Representations
MoonL88537 · x · 2026-07-18
The author shared a reproduction of Anthropic's J-space analysis, expanding it with two new experiments:
- Representation structure of Inkling 1T: It acts more like an "outlier" compared to other models, lacking clear separation between perception/workspace/action blocks and maintaining a near-identical geometric structure across all layers. The early-to-late layer CKA metric is around 0.8, whereas other models score around 0.5.
- Impact of Quantization: The J-space of @poolsideai's Laguna XS 2.1 was compared between bf16 and nvfp4, showing almost no difference. The quantized model shares the exact same JLens space as the unquantized version.
The author also noted that both J-space checkpoints have been uploaded to Hugging Face.
More from Research
- LoMa Paper Ships REALLY HardPairs Dataset, Accepted at ECCV 2026 — ducha_aiki · 2026-09-11
- Johns Hopkins Launches Full-Stack Hands-on Robot Learning Class with SO-101 Arm Kits — _krishna_murthy · 2026-09-11
- SyncWorld: In-Context Robot World Model Simulates Unseen Views and Embodiments Zero-Shot — ChongZzZhang · 2026-09-11
- A 3D Pose Dataset for Dogs Released — ducha_aiki · 2026-09-11
- Five tells that still make AI video read as AI, from physics glitches to missing operators — NewPhoneWhotiz · 2026-09-11
- AnyMatch accepted to ECCV 2026 with a NoPresenter design — ducha_aiki · 2026-09-11