# Structure AL diversity arm (Option B exploratory)

**`prop02_success_claimed`: False.** Leakage diag already filed (`structure_al_leakage_diag.md`).

## Setup
- N=5000 Magpie-lite; seed=100; batch=25; budget=400; seeds=5
- Diversity = farthest-point in scaled fingerprint space

| arm | final recall ± std | CI95 | AULC ± std |
|---|---:|---:|---:|
| random | 0.1043 ± 0.0059 | [0.0992, 0.1094] | 0.0627 ± 0.0064 |
| uncertainty | 0.3018 ± 0.0100 | [0.2930, 0.3106] | 0.1602 ± 0.0081 |
| diversity | 0.0534 ± 0.0037 | [0.0502, 0.0566] | 0.0333 ± 0.0019 |

Figure: `figures/track2_structure_al_diversity_arm.png`

## Limits
Secondary fingerprint track only; not Prop-02 support. GNN remains primary for official support.