Study 01 · A17 · October 2, 2026
Whisper Small learned, but missed the quality target.
A corrected LoRA pipeline reduced normalized WER from 52.58% to 31.02%. The fresh 4,000-step run completed and its outputs passed local audits. The below-25% gate failed.
The corrected sweep
All three ranking arms ran for 1,500 steps. The selected rate, 1e-3, was then trained fresh for 4,000 steps. Smaller rates performed worse within the ranking budget. This single-seed sweep does not establish a universally optimal rate.
| Run | Learning rate | Selected step | WER % | CER % | Training min |
|---|---|---|---|---|---|
| Base model | — | — | 52.58 | 21.58 | — |
| Ranking 1e-3 | 1e-3 | 1500 | 30.95 | 12.96 | 30.47 |
| Ranking 3e-4 | 3e-4 | 1500 | 35.72 | 14.44 | 30.68 |
| Ranking 1e-4 | 1e-4 | 1500 | 40.38 | 18.22 | 30.85 |
| Fresh final | 1e-3 | 4000 | 31.02 | 12.69 | 86.83 |
The final’s WER was 0.0758 percentage points higher than the short reference. These fresh runs had different linear-decay budgets, so this does not isolate the effect of 2,500 additional updates.
Checkpoint evidence
Learning, an unexplained spike, then a plateau.
At step 1,200, evaluation WER rose to 99.17% and recovered to 33.72% at step 1,400. The cause was not isolated. Late checkpoints fluctuated around 31–33% WER.
Exact final-run checkpoint values appear in the table below.
Inspect all 20 final-run checkpoints
| Step | WER % | CER % | Evaluation loss |
|---|---|---|---|
| 200 | 40.8867 | 16.5209 | 0.8704 |
| 400 | 39.2952 | 15.8241 | 0.8367 |
| 600 | 36.9079 | 15.5282 | 0.8004 |
| 800 | 38.5373 | 17.8424 | 0.8199 |
| 1000 | 34.1038 | 14.2857 | 0.8100 |
| 1200 | 99.1664 | 69.1999 | 5.0383 |
| 1400 | 33.7249 | 14.0490 | 0.8461 |
| 1600 | 35.2027 | 14.7854 | 0.8366 |
| 1800 | 33.4218 | 13.9964 | 0.8543 |
| 2000 | 33.2702 | 14.0096 | 0.8456 |
| 2200 | 31.8681 | 13.3785 | 0.8368 |
| 2400 | 33.1186 | 13.7598 | 0.8667 |
| 2600 | 31.5650 | 13.1287 | 0.8621 |
| 2800 | 31.4513 | 12.9314 | 0.8827 |
| 3000 | 31.1482 | 12.8788 | 0.8960 |
| 3200 | 32.0955 | 13.0958 | 0.8820 |
| 3400 | 32.6639 | 13.4771 | 0.9008 |
| 3600 | 30.8450 | 12.7079 | 0.9090 |
| 3800 | 31.2239 | 12.7145 | 0.9150 |
| 4000 | 31.0345 | 12.6882 | 0.9165 |
Performance was uneven.
| Speech type | Clips | WER % | CER % |
|---|---|---|---|
| Read | 160 | 29.55 | 15.39 |
| Spontaneous | 187 | 32.50 | 9.83 |
The worst-scoring evaluation speaker had 62.70% WER across 37 recordings. A 25-row text review found phrase substitutions and spelling disagreements, but listening and the broader A13 data audit remain pending. Text coincidences alone do not prove incorrect audio alignment.
Recipe and checks
| Setting | Executed value |
|---|---|
| Base | openai/whisper-small |
| Adaptation | LoRA rank 32 · alpha 64 · q_proj / v_proj · dropout 0.05 |
| Batch / seed | Effective batch 16 · seed 20260816 |
| Precision | Float16 training · fresh float32 scoring |
| Decoding | Greedy, forced Tagalog transcription, length cap 83 |
| Normalization | NFKC, lowercase, trimmed and collapsed whitespace. Punctuation retained. |
Real examples verified decoder-start token handling before training. All 38 checkpoint directories retained complete resume state. All 2,776 base/adapter predictions and speaker/speech-type slices were independently recomputed locally.
What we carry into the next run
- L1 · Check the real data path. Keep label-prefix assertions, save/reload checks, and pinned scoring.
- L3 · Judge recognition, not training loss alone. Low training loss did not translate into lower late-stage WER.
- L4 · Capture anomalies deliberately. Batch identities, gradient norms, and loss-scaler changes are proposed checks for a relevant repeat, not completed instrumentation.
- L5 · Audit before choosing the intervention. A13 will review at least 100 errors and roughly 500 training examples.
Download and provenance
Audited locally against the retained private run artifacts. This public snapshot contains aggregate results and checkpoint curves, not audio or per-example transcripts.
Frozen model and data identifiers
- Whisper base revision
973afd24965f72e36ca33b3055d56a652f456b4d- Training manifest SHA-256
b91db8fb8d1f2ed6ee166b94639981c875187d6eb8f701f25f67727be2621aaf- Evaluation manifest SHA-256
dffdcf9b4c33a17b9b347acba819cb48279773dd3a8ac568957cd65edd607e36
No dataset audio, per-example transcripts, private host details, or credentials are included in this public results snapshot.