Re: Heirarchical menus limit

["Mark A. Tapia" <markt@dgp.toronto.edu>]

On Mon Nov 22, Daniel Ranson states that the limit for nesting
hierarchical menus is 5 and that the guidelines say *1*. 

You might be interested in the results of Gord Kurtenbach's Ph.d.
dissertation (1992) at the University of Toronto. Gord developed
a technique for marking menus - allowing them to be self-revealing
and to support the smooth transition between expert and novice.
The choice in a marking menu depends on traveling a minimum distance
in a particular direction. Standard menus depend on exact linear
distance (with the result of hysterisis - overshooting or undershooting
the menu item and then correcting. The situation becomes worse using
hierarchical menus - vertical motion must be combined with horizontal
motion). In marking menus, the user can "mouse" ahead, leaving an
ink trail. The mark with n turns is interpreted as a choice from  n+1
nested menus. Gord determined that menus with 2, 4, 8, and 12 items
were practical. 8 seemed to be the practial maximum, at most 3 levels
deep (allowing 512 choices). 

The file /ppub/MCL2/contrib/menu-enhancements.sit.hqx available
by anonymous ftp from cambridge.apple.com is an MCL implementation
of marking menus. The package introduces marking-menu-view, a new
class of views. This allows you to associate menus with views.

mark