13. Sign-convention detection & repair (owner hypothesis) — screening
Tag: sign-convention · idea #13 · index
- Hypothesis: a small set of community repos encodes joint angles with flipped sign conventions (esp. wrist_roll on mirrored wrist-cam mounts); training on them injects contradictory supervision.
- Status: stage 1 (CPU screen over the panel npz) done 2026-08-05
— 9 candidate (repo, dim) cells, three pathologies separated by
per-frame classification; cleanest mirror lead
kantine/domotic_dishTidyUp_anomaly wrist_flex (median frame corr
−0.75). Instrument:
probes/probe_sign_convention_stage1.py; results post. - Stage 2 PRE-REGISTERED (2026-08-05 ~23:3xZ, pre-reg): optical-flow cross-check on the three mirror-signature cells (dishTidyUp_anomaly wrist_flex, groceriesSorting_expert wrist_roll, aractingi shoulder_lift), CPU-only (~20–40 min spare cores). Frozen: Farneback params, isolated-motion pair selection (|v_d| ≥ 0.5°/frame, 2× dominance), ego-cam identification rule (cams are unlabeled), 15-repo so100 reference population with an 80% sign-consistency validity gate, MIRRORED/NORMAL/INCONCLUSIVE bootstrap rules, synthetic-flip hard validation gate before candidate cells open, Dongkkka + kevin510 as specificity controls, and the stream- consistency read (calibration-mirror vs action-only flip). Feasibility verified pre-post: all repos local, torchcodec decodes the AV1 videos, state+action parquet intact. Execution = a later work session; if ≥1 MIRRORED, the repair arm (flip-corrected derived corpus through #18.8 certs + paired screen) gets its own pre-reg.
- Stage 2 EXECUTED 2026-08-05 ~23:5xZ — the escalation branch fired
(results post, probe
probes/probe_sign_convention_stage2.py): 3 of 4 reference populations FAILED the 80% sign-consistency gate (wrist_roll 9/15, wrist_flex 10/15, shoulder_lift 9/15; only shoulder_pan valid at 13/15) ⇒ hard gate failed, candidate cells never opened, no verdicts. The t_x oracle PASSED end-to-end (mass 1.000 both directions) — the mechanism works where the population premise holds. Diagnosis: image-plane statistic signs follow camera mounting (cams sign-disagree in 11/15 shoulder_lift refs; ego-cam rule NO-MARGIN on ~half; ω underpowered off-wrist-cam) — not evidence that joint conventions vary corpus-wide. The three stage-1 mirror cells remain unresolved leads; repair arm neither eligible nor dead. Next (owner steer wanted): stage-2b amendment conditioning reference populations onmeta/camera_kinds.json(the 2026-08-02 VLM cam-labeling pass: wrist/front/side/top) — t_y from front cams, ω from wrist cams, label-gated ego rule; reuses the 38-repo flow cache, so it is cheap.