Introducing game elements in crowdsourced video captioning by non-experts

Video captioning can increase the accessibility of information for people who are deaf or hard-of-hearing and benefit second language learners and reading-deficient students. We propose a caption editing system that harvests crowdsourced work for the useful task of video captioning. To make the task an engaging activity, its interface incorporates game-like elements. Non-expert users submit their transcriptions for short video segments against a countdown timer, either in a "type" or "fix" mode, to score points. Transcriptions from multiple users are aligned and merged to form the final captions. Preliminary results with 42 participants and 578 short video segments show that the Word Error Rate of the merged captions with two users per segment improved from 20.7% in ASR to 16%. Finally, we discuss our work in progress to improve both the accuracy of the collected data and to increase the crowd engagement.