hypothesis to be tested:
  1. bookmark is more efficient than video playback (individual work, collaborative work, expert/novice training)
  2. bookmark is preferred by users than video playback
Tasks can be medical interrogation, CAD work (car modeling etc), LEGO models
It is useful for other software tutorials too.
Abstract
% state the problem
% why it's an interesting problem
% what my solution achieves
% what follows from my solution