Optimal number of choices per menu for naive users of a computer-answered telephone system

With the high volume of telephone calls being placed to businesses and community organizations, computer technology is being used to answer and route calls. In order to access information, callers go through a series of auditory menus from which they must select the appropriate option from each menu. Callers must rely on short-term memory since information is rarely preserved for review visually. This paper investigates the structure of the menus as they are arranged in a hierarchical tree. Three configurations were chosen for study: menus with 2, 4, or 8 choices per menu. Eighteen subjects were tested on a simulated system, placing calls as they might at home or the office. With 64 items in the database, 2-choice menus require the subject to listen to and choose from 6 different menus. The 4-and 8-choice menus require 3 and 2 menus, respectively. Subjects navigated through the system of menus and reached the correct information in less time and with fewer errors with the 4-choice and 8-choice menus than they did with the 2-choice menus. In a questionnaire, two-thirds of the subjects preferred 4-choice menus. Experience with other computer-answered telephone systems was not a significant factor in the subjects' performance.