Word Error Rate
An ASR accuracy metric defined as substitutions plus deletions plus insertions divided by the number of reference words.
Speech Processing Context
Word Error Rate is computed as (S + D + I) / N, where substitutions, deletions, and insertions are measured against the number of reference words. Text normalization, punctuation, number formatting, casing, and tokenization must be fixed before benchmark results are compared.
Evaluation Boundary
A lower WER does not imply a better system for every application. Speaker attribution, timestamp quality, latency, domain-critical words, and error severity may need separate metrics.
Related Speech Processing Concepts
Related technical article: Automatic Speech Recognition.