Bookmark Claims

A bookmark

allows the user to directly manipulate the device which holds the page [Direct manipulation]
is a metaphor of a familar device used with real books for the same purpose [Metaphor]
provides a device whereby users can return to a known position in the notebook after having moved from that position
but use of auxiliary metaphors connected to the main notebook metaphor may overwhelm novice users with computer representations of real world items
but the actions associated with a real bookmark may not be easily translated into commands to manipulate the computer bookmark