Transcription Accuracy: What the Numbers Really Mean

When evaluating transcription services, you'll see impressive accuracy claims: 99%, 99.5%, even 99.9%. But what do these numbers actually measure?

Most accuracy metrics are calculated using Word Error Rate (WER)—the percentage of words that are transcribed incorrectly. However, this metric can be deceptive:

• It measures edit distance, not usability
• A single wrong word in 100 is counted as 1% error
• But context matters: "their" vs "there" might be 1% error but 100% wrong for meaning
• Different audio conditions (background noise, accents, technical jargon) dramatically affect real-world performance

What actually matters:

• Accuracy on YOUR type of content (meetings, podcasts, interviews, etc.)
• Handling of technical terminology
• Speaker diarization quality
• Punctuation and paragraph breaks

At Celeritas, we focus on metrics that matter for real work: actionable transcripts that capture not just words, but context and meaning.