Streaming video on the World Wide Web is being widely deployed, and workpla
ce training and distance education are key applications. The ability to ann
otate video on the Web can provide significant added value in these and oth
er areas. Written and spoken annotations can provide 'in context' personal
notes and can enable asynchronous collaboration among groups of users. With
annotations, users are no longer limited to viewing content passively on t
he Web, but are free to add and share commentary and links, thus transformi
ng the Web into an interactive medium. We discuss design considerations in
constructing a collaborative video annotation system, and we introduce our
prototype, called MRAS. We present preliminary data on the use of Web-based
annotations for personal note-taking and for sharing notes in a distance e
ducation scenario. Users showed a strong preference for MRAS over pen-and-p
aper for taking notes, despite taking longer to do so. They also indicated
chat they would make more comments and questions with MRAS than in a 'live'
situation, and that sharing added substantial value. (C) 1999 Published by
Elsevier Science B.V. All rights reserved.