.title
Pie Menu Direction

.synonyms
direction

.definition
How pie menus use direction.

.contents

	Menu designers can take advantage of the directional aspect of pie
	menus in several ways. 

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.tab 0 .line CIRCULAR LAYOUT
	Their circular layout is very appropriate for certain applications.
	Spatially oriented items can be placed in their corresponding
	directions, pairs of complementary items can be placed in opposite
	directions, and orthogonal items can be placed at right angles. Other
	natural and intuitive arrangements are possible, such as compasses and
	clock dials. (Hopkins, et al, 1987)
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.tab 0 .line SELECTING WITHOUT LOOKING
	Because pie menus are based on direction of relative mouse
	movement, they do not require a lot of visual attention to use. An
	experienced pie menu user can make selections fairly reliably from a
	familiar, reasonably sized menu, without even looking at the display!
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.tab 0 .line MOUSE AHEAD
	One of the nicest advantages of pie menus is that they work very well
	with "mouse ahead". Mouse ahead is when the user gives commands to the
	computer with the mouse more quickly than the computer can process,
	but instead of ignoring the commands, the computer buffers them, and
	processes them all in order.  Because it possible to use a pie menu
	without seeing it, experienced pie menu users are able to mouse ahead
	through several levels of nested menus without waiting for them to be
	displayed.
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.tab 0 .line DISPLAY SUPPRESSION
	With mouse ahead display suppression, a menu is not displayed on the
	screen if the user mouses ahead through it quickly enough. If the user
	completes the selection before the menu can be displayed, it is no
	longer necessary for the user to see the menu, if feedback is not
	required, or if acting on the selection provides feedback.
	Experienced users can learn to "chunk" multiple selection actions into
	single gestures that can be performed quickly and automatically
	(Buxton, 1986), and can utilize mouse ahead display suppression more
	often than a novice user.  This feature speeds up interaction
	considerably if the user is fast or the system is unresponsive.

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	==> .~ Distance~