Audio interfaces are becoming increasingly popular, and the design of such interfaces presents its own peculiar problems. Resnick and Virzi describe a collection of design styles for audio and interactive voice response applications that take into account the special characteristics of audio interaction. These design styles are discussed in the context of menu, list, and form dialogues. The authors define a design space based on the intent of user actions (for example, movement between parts of the dialogue). They describe several interaction styles based on choices for the effects of such actions (such as move forward and move back). Considerations relating to designing for users who have different levels of expertise with the interface are also discussed. The results are expected to be useful not only for telephone interfaces, but also for audio interaction with workstations, personal digital assistants, handheld computers, and similar devices.

The paper is clearly written and well illustrated, though there is some confusion in the captions and numbering for figures 25 through 27. Interface designers and usability experts will find it extremely useful as a basis for guidelines on audio interface design and a source of tips on interaction style, in conjunction with other HCI work. HCI researchers will be interested in the ramifications of the design space and interaction style concepts.