The Depth/Breadth Tradeoff in Hierarchical Computer Menus

Abstract

Goal acquisition speed and accuracy were compared for subjects using four different menu configurations of a semantic hierarchy on an interactive computer terminal. Depth (the number of menu levels) varied from one to six, while breadth (the number of choices per menu) varied from two to 64. Goal acquisition time for the four experimental groups produced a U-shaped function with a minimum at the configuration of two levels with eight choices per level. Error data corroborated the acquisition times demonstrating that the fastest conditions also produced the least errors. Optimization of the depth/breadth tradeoff can be an important design consideration in goal acquisition tasks requiring speed and accuracy.