ABSTRACT

	     Directional Selection is Easy as Pie Menus!

			     Don Hopkins
			University of Maryland

		    Simple Simon popped a Pie Men-
			u upon the screen;
		    With directional selection,
			all is peachy keen!

Pie Menus provide a practical, intuitive, efficient way for people to
interact with computers. They run circles around buttoned-down
square old pull down menus, in both capability and convenience. 

The choices of a Pie Menu are layed out in a circle around the cursor,
so the direction in which you move makes the choice, allowing the
distance moved to be used in other ways; essentially, Pie Menus have
two outputs: direction and distance, each of which can be continuous
or discrete. They are useful for multifarious forms of input, and work
with many different types of input devices.

They furnish a general purpose two dimensional form of input, which
works with many different types of hardware.

Their circular nature makes them especially well suited for spatially
oriented selections. Menu choices can be positioned in mnemonic
directions, with complementary items across from each other,
orthogonal pairs at right angles, and other natural, intuitive
arrangements.

Once familiar with selection directions, you can make choices from Pie
Menus in quick, easily remembered strokes, without even having to see
the menus. There is no need to divert your visual attention to make a
choice, as pull down menus demand of you. 

Experiments comparing the two methods have shown that people can
choose items faster and with fewer errors from Pie Menus than from
pull down menus. They are straightforward and simple to master, and
they facilitate a swift, fluent, natural style of human computer
interaction.