Caption Quality

The overall fitness of a set of captions or subtitles for their intended accessibility purpose. Quality is multi-dimensional: it includes text accuracy (whether spoken words are correctly transcribed, commonly measured by Word Error Rate or the NER model), synchronicity with the audio, latency in live captioning, readability (font, color contrast, line-length, segmentation), speaker identification, handling of non-speech sounds, and caption placement — in particular whether captions occlude important on-screen content. Caption quality is regulated in many jurisdictions (e.g., the U.S. FCC closed-captioning quality rules, the UK Ofcom subtitling guidelines, BBC Subtitle Guidelines) and is the subject of ongoing research into automated metrics that reflect Deaf and Hard-of-Hearing viewers' actual experience.