The effects of digital video quality on learner comprehension in an american sign language assessment environment

Abstract

The effects of digital video framerate and size on American Sign Language (ASL) learner comprehension were investigated. Fifty-one students were randomly assigned to one of three video size treatment groups: 480x360, 320x240, and 240x180 pixels. Within each treatment, students were presented three 30-second videos of signed narratives at framerates of 6, 12, and 18 frames per second. Participants used ASL to retell each story and performances were captured by a digital video camera and archived for evaluation. Three ASL experts evaluated the video performances and generated a fluency score for each student. The results indicate that framerate and the interaction between framerate and ASL level had significant effects on learner comprehension, but video size did not significantly affect learner comprehension. These results are used to generate framerate and video-size recommendations for displaying and recording student performance and instructor feedback videos in an ASL performance assessment software environment.