| --- |
| license: apache-2.0 |
| tags: [automatic-speech-recognition, librispeech, error-analysis] |
| --- |
| |
| # Worst-100 test-clean clips — audio, transcripts, and the vocabulary finding |
|
|
| The 100 LibriSpeech test-clean clips where the block-4 production model (4.60% WER) made |
| the most word errors — with audio embedded so the failures can be *listened to*, plus the |
| model's transcript next to the reference for each clip. |
|
|
| ## The finding this dataset produced |
|
|
| **47% of the word errors in these clips are on words that never appeared in the 30-hour |
| training vocabulary at all** (20,066 distinct words seen). The model was not mishearing |
| these words — it had never met them. Repeat offenders are book-specific names (rodolfo, |
| montrose, boolooroo). Full breakdown in `worst100_oov_analysis.json`. |
|
|
| This measurement is the primary justification for the 100-hour training phase: a coverage |
| problem calls for coverage. See `Diffusion-ASR/pipeline-code-and-docs` for the full recipe |
| and evidence record. |
|
|
|
|
| ## How to read this dataset (verified 2026-08-11) |
|
|
| - **Ranking basis:** clips are ranked by **absolute word-error count** on |
| **Whisper-normalized** text — not by WER percentage. A long clip with 20 errors at 23% |
| WER outranks a short clip at 60%. |
| - **Tie band:** the rank-100 cutoff is 4 errors, and 66 clips tie at exactly 4 — which of |
| them appear here is arbitrary among equals. |
| - **`substitution_pairs` are raw alignment output**, not claimed confusions: across a |
| garbled stretch, positional pairing produces items like `have→all` that carry no |
| meaning individually. Use `error_classes` for interpretation. |
| - Some references contain **genuine dialect spellings** (e.g. `allers`) — that is the |
| LibriSpeech ground truth, not a transcription error. |
| - Integrity verification: all 100 references byte-match the official test-clean |
| transcripts; all 100 hypotheses byte-match the model's recorded decode outputs; stored |
| error counts reproduce exactly under the stated normalization. |
|
|
