# Scoliosis1K Dataset Analysis (1:1:8, shared-align skeleton maps)

## Split

Train counts:
- negative: 596
- neutral: 74
- positive: 74

Test counts:
- negative: 204
- neutral: 126
- positive: 419

## Raw pose quality

Mean keypoint confidence by split/class:
- train negative: 0.9016
- train neutral: 0.9023
- train positive: 0.8987
- test negative: 0.9009
- test neutral: 0.9020
- test positive: 0.8999

Mean valid-joint ratio (`conf > 0.05`) by split/class:
- train negative: 1.0000
- train neutral: 1.0000
- train positive: 1.0000
- test negative: 1.0000
- test neutral: 1.0000
- test positive: 1.0000

## PAV signal

Mean normalized PAV value by label:
- negative: 0.3068
- neutral: 0.3546
- positive: 0.3635

Train-on-train / test-on-test linear softmax probe over sequence-level PAV:
- accuracy: 50.87%
- macro precision: 50.50%
- macro recall: 48.19%
- macro F1: 39.88%

## Shared-align heatmap geometry

Combined support bbox stats over all sequences:
- width mean / p95: 32.13 / 33.57
- height mean / p95: 61.52 / 61.61
- active fraction mean / p95: 0.3634 / 0.3738

Per-sequence temporal jitter (std over frames):
- center-x std mean / p95: 0.864 / 1.243
- center-y std mean / p95: 0.516 / 0.704
- width std mean / p95: 2.152 / 2.804
- height std mean / p95: 0.507 / 0.545

Residual limb-vs-joint bbox-center mismatch after shared alignment:
- dx mean / p95: 0.195 / 0.229
- dy mean / p95: 0.251 / 0.357

Estimated intensity mass in the columns removed by `BaseSilCuttingTransform`:
- mean clipped-mass ratio: 0.0000
- p95 clipped-mass ratio: 0.0000

## Reading

- The raw pose data does not look broken. Confidence and valid-joint ratios are high and similar across classes.
- The sequence-level PAV still carries useful label signal, so the dataset is not devoid of scoliosis information.
- Shared alignment removed the old limb-vs-joint registration bug; residual channel-center mismatch is now small.
- The remaining suspicious area is the visual branch: the skeleton map still has frame-to-frame bbox jitter, and the support bbox is almost full-height (`~61.5 / 64`) and fairly dense (`~36%` active pixels), which may be washing out subtle asymmetry cues.
- `BaseSilCuttingTransform` does not appear to be the main failure source for this shared-align export; the measured mass in the removed side margins is near zero.
- The dataset itself looks usable; the bigger issue still appears to be how the current skeleton-map preprocessing/runtime path presents that data to ScoNet.