Evaluation method
How we evaluate bilingual lesson transcription
A useful classroom transcription test must measure more than word accuracy: it should also check language switching, speaker attribution, timestamp usefulness, and the teacher’s correction effort.
Short answer
Evaluate bilingual lesson transcription on representative teacher–student recordings, create a human-checked reference transcript, and report errors separately for words, language switches, speakers, and timestamps. Publish the audio conditions and limitations so results can be interpreted rather than treated as a universal accuracy claim.
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- Use consented or synthetic recordings that reflect real lesson patterns.
- Keep the same audio and reference transcript for every system tested.
- Report failure cases and review effort, not only one aggregate score.
1. Build a representative lesson set
Include teacher prompts, student answers, corrections, repetition, short interruptions, and natural switches between English and the learner’s language. Record audio condition, duration, speakers, language pair, and the number of language switches.
2. Create a human-checked reference
A fluent reviewer should transcribe the words, mark speaker turns, and retain meaningful hesitations or self-corrections. A second review is useful for ambiguous names, accents, and overlapping speech.
3. Measure transcription errors and language spans
Word error rate can summarize substitutions, insertions, and deletions, but report language-specific results when possible. Annotate language spans around code-switches and count spans that are dropped or incorrectly rewritten because one average can hide these failures.
4. Measure speaker attribution
Count speaker turns assigned to the wrong person and note whether the system merges or fragments speakers. In a tutoring transcript, a correctly recognized sentence attributed to the wrong speaker can still make the feedback unusable.
5. Check timestamp usefulness
Test whether a tutor can use the timestamp to return to the relevant sentence quickly. Record large timing drift or segment boundaries that split a correction from the sentence it explains.
6. Record human review effort
Time transcript correction and feedback extraction separately. Define the timer boundaries before starting, record the reviewer role and feedback task, and report both values with the audio duration. This reflects practical value better than recognition accuracy alone.
What this page does not claim
Tutor Transcript has not published a universal best-accuracy claim. Results can vary with language pair, accent, microphone, noise, overlap, lesson structure, and reference-transcript choices. Future result pages should link to the exact test set and method used.
Frequently asked questions
Is word error rate enough for bilingual lessons?
No. It does not fully represent language-switch retention, speaker attribution, timestamp quality, or the teacher’s review effort.
Should real student recordings be published?
Only with appropriate consent and privacy protection. Synthetic or specifically consented samples are safer for a public benchmark.
Why publish failures?
Failure examples help tutors judge whether the tested conditions resemble their own lessons and make comparisons more credible.
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