BAYCHI October Meeting Report: Natural Selection: The Evolution of Pie Menus, October 11, 1998
By John D’Ignazio
[BayCHI is our sister SIGCHI local chapter in the San Francisco Bay area. BayCHI meeting reports are extracted with permission from the BayCHI news- letter, and are copyright by BayCHI.]
The October 11 BayCHI meeting occurred in two parts. The first featured Don Hopkins, who gave a talk entitled “Natural Selection: The Evolution of Pie Menus,” along with demonstrations of various pie menu interfaces he’s constructed over the years.
Hopkins has worked as both a migrant research programmer and as a real-world software developer. He’s currently working at Maxis on a family simulation game designed by Will Wright, called “The Sims.”
Hopkins began his tour through user interface innovations with pie menus by showing a videotaped demo of his X10 and X11 window managers.
Pie menus appealed to Hopkins because they conform to the rule that the user’s attention should not be squandered. A pie menu selection offers direct feedback versus a user selection that brings up intermediate menus. The programmed pie menu ignores users’ gestures except the motions to select or cancel. Hopkins uses pie menus because they take advantage of Fitts’ Law, which relates fast selection speed and low error rate to the pie menus’ large target size and small distance between selections.
Hopkins’ experiments with pie menus showed they are best when the selections that appear in a particular segment don’t change. He demonstrated a scrolling pie menu but said that a fixed display with an even number of items was ideal, up to eight slices. Commands related to geometry or physical movement in an environment functioned well as pie menu selections, because the commands’ physical nature maps well onto the pie menu format. Hopkins demonstrated how pie menus are easy for novice users, who follow the directions, and efficient for experienced users, who can quickly “mouse ahead” once they know the way.
Creative applications of pie menus that Hopkins demonstrated used the structure of the user’s activity in the pie menu design. One was a color wheel with the gradations around the circle. Another was a pie menu that allowed you to select a font and pick a size by moving the cursor either towards the pie’s center for smaller size fonts or away for larger fonts. On another menu, a user selected the value of an angle by bending a line with cursor movements to increase or de- crease the angle’s value. To select from a large number of possible values, the user scrolled through the values of a pie menu that were presented edge on, with the multiple values appearing to stand out as if they were written across many small wedges of the pie crust.
Turning from his video demonstrations to a PC, Hopkins demonstrated an ActiveX applet that he wrote which works with programs written in a wide range of software running in Windows. The pie menu applet has simple menu syntax, uses control panels and shows the menu’s properties to whatever soft ware is accessing it.
Hopkins’ software is available from his Web site at:
The pie menu software also supports good pie menu design automatically. For instance, if you specify three selections, room for an even number of selections appears.
Hopkins showed that the software can handle numerous possible selections by presenting overlapping pie-like shapes above and below the original menu that the user can scan through and highlight.
The motif of the pie menu is variable: there are radiating spokes, a punched-out look, and radiating balloons that are best for text selections.
Hopkins concluded by demonstrating the use of pie menus in the new game he’s working on at Maxis. In a colorful, 3-D environment, the user builds and furnishes a house for a cast of characters. Pie menus of various designs and complexity appear frequently, such as to maneuver throughout the environment, situate objects, and select actions or characteristics of the game’s actors. The last example was the most complicated and required the user to point a character’s 3-D head around a full circle toward various selections that appeared over a desaturated portion of the game.
