Effectiveness of real-time automated captions and subtitles as a text-based alternative to auditory information in Universal Design for Learning

Automated real-time captions and subtitles are useful for implementing Universal Design for Learning (UDL) Checkpoint 1.2 that suggests offering a text-based alternative to auditory information for all learners to access the content equally. The purpose of this study was to determine the effectiveness of the Microsoft PowerPoint Live feature of automated real-time captions/subtitles in English and Spanish. The word accuracy (WAcc) of the captions and the intelligibility scores (IS) of the subtitles were obtained to determine the effectiveness. Five native English- and 5 native Spanish-speaking participants read a prepared script in their native language. The average WAcc of captions in English was 96.3%, and the average WAcc of captions in Spanish, which included special terms, was 87.9%. On average, the IS of subtitles in Spanish (1.74) was better than the IS of subtitles in English (2.06). The WAcc of captions in Spanish excluding special terms (96.2%) yielded an IS of subtitles in English of 1.75. The researchers cautiously concluded that automated real-time captions/subtitles generated by PowerPoint Live in English or Spanish could be useful to implement UDL Checkpoint 1.2, mainly when the viewer can hear the presenter and is fluent in the presenter's spoken language.