Pies: Implementation, Evaluation, and Application of Circular Menus
	  By Don Hopkins, Jack Callahan, and Mark Weiser
	  (Paper in preparation. Draft available from authors.)

	  Introduces Pie Menus, a new type of menu whose choices are
	  positioned a circle around the cursor, like the slices of a
	  pie.  They are compared and contrasted with pull down menus,
	  and ideas about their usage and applications are discussed.

	A Comparative Analysis of Pie Menu Performance
	  By Jack Callahan, Don Hopkins, Mark Weiser, and Ben Shneiderman
	  Proc. CHI'88 conference, Washington D.C.: available from ACM, NY.

	  Details the design, procedures, and results of an experiment
	  comparing Pie Menus with pull down menus. The experiment
	  compared the selection time and error rate for choices from
	  Pie and pull down menus of eight items. Menu tasks were
	  classified by the type of their selections, as Pie type
	  tasks, linear type tasks, and unclassified type tasks.  Pie
	  menus were shown to be significantly faster and more


	Directional Selection is Easy as Pie Menus!
	  By Don Hopkins
	  ;login: The USENIX Association Newsletter
	  Volume 12, Number 5; September/October 1987; Page 31
	  Summary of the Work-in-Progress talk given at the 1987 Summer
	  Usenix Conference in Phoenix.

	  Covers some problems encountered and tricks learned in the
	  implementation and testing of Pie Menus, proposed
	  interaction techniques and applications, as well as
	  philosophical discourse on choice grouping and placement,
	  display style, and input asthetics.

	A Pie Menu Cookbook: Techniques for the Design of Circular Menus
	  By Don Hopkins
	  (Paper in preparation. Draft available from author.)

	  Describes the design of efficient and easy to use pie menu
	  selection techniques. Pie menus are a fast, accurate way of
	  using a mouse to select from items displayed on the screen.
	  They have several advantages over traditional linear menus,
	  and many practical applications. Describes characteristics
	  and distinctions of pie menus and gives examples of pie menu
	  applications that take advantage of these qualities.
	  Suggests general principles and heuristics for effective pie
	  menu design, that can be applied to other applications.