Designing Effective Speech Interfaces

User Expectations

One of the biggest challenges in the design of speech interfaces is dealing with user expectations. Users expect talking computers to understand more than they are capable of, and to provide more information than they are capable of. Your interface design can help set appropriate expectations.

Identify the Computer

Users will adjust their speech and their expectations if they know they are interacting with a computer and not with a human. They will speak more briefly and exactly, and enunciate more clearly. Let the users know up front that they are speaking to a computer. For example, start an interaction with “Welcome to the XYZ Voice Response System. What directory to you want to search for?” rather than “What directory do you want to search for?”

Let the users know up front that they are speaking to a computer.

Use enough words and a long enough greeting to convey this information. In a study by Susan Boyce (1999), she used different versions of a greeting. The first three were recorded human voices:

“AT&T. How may I help you?” (Standard version)

“AT&T Automated Customer Service. How may I help you?” (Short automated version)

“AT&T Automated Customer Service. This service listens to your speech and sends your call to the appropriate operator. How may I help you?” (Long automated version)

In a fourth version, the long automated version was used but it was played with a computer-synthesized voice rather than a human voice. Both longer versions resulted in ...