Collaborative Editing For Improved Usefulness And Usability Of Transcript-Enhanced Webcasts

One challenge in facilitating skimming or browsing through archives of on-line recordings of webcast lectures is the lack of text transcripts of the recorded lecture. Ideally, transcripts would be obtainable through Automatic Speech Recognition (ASR). However, current ASR systems can only deliver, in realistic lecture conditions, a Word Error Rate of around 45% - above the accepted threshold of 25%. In this paper, we present the iterative design of a webcast extension that engages users to collaborate in a wiki-like manner on editing the ASR-produced imperfect transcripts, and show that this is a feasible solution for improving the quality of lecture transcripts. We also present the findings of a field study carried out in a real lecture environment investigating how students use and edit the transcripts.