Increased Content Knowledge of Students with Visual Impairments as a Result of Extended Descriptions

Abstract

The National Center for Accessible Media has developed a technology and protocol for inserting extended, enhanced descriptions of visually based concepts into artificially paused digital video. These “eDescriptions” describe material not fully explained by a narrator and provide analogies and explanation specifically designed for students who are visually impaired. In two experiments, fourth-grade students with visual impairments listened to video clips of narrated, age-appropriate curricular material with eDescriptions inserted along different organizational frameworks, as well as video with only standard narration. Students were first assessed on prior knowledge of the content to be covered in the videos. After three weeks, each student listened to the videos and answered questions assessing content acquired from the presentations. Students performed better on content tests for material that included eDescriptions than for material that only had standard narration. This effect was strongest when eDescriptions were placed prior to relevant material in a video. While the most effective strategy was using descriptions followed by the relevant video, both students and teachers preferred hearing a word first, followed by its definition. Other elements determined important to the creation of effective eDescriptions included selection of developmentally age appropriate vocabulary, length of individual eDescriptions, and overall length of a video when eDescriptions were added. The usefulness of eDescriptions for increasing acquisition of content information points to the need for further research into auditory description.