Callers can complete their tasks more quickly if they can respond consistently. The response becomes more automatic if users can use the same words and phrases in similar situations. Here are several ways to increase response consistency:
Consistent use of commands. Use the same command for the same task in all applications. For example, use the command goodbye in all applications instead of using goodbye in one application, stop in another application, and hang up in a third application.
Consistent format for similar data. In addition to presentation consistency, callers prefer to respond to similar prompts by speaking the same words in the same order. For example, when asked for a birth date, start date, end date, or any other kind of date, the caller should be encouraged to respond by using the same format. In North America, this sequence is usually the month, the day, and finally the yearwith the name of the month, the day in ordinal format (thirteenth), and then the year (often only the last two digits of the year: "02")
If applications reuse standard dialog modules, then callers will learn how to interact with these modules when they are first encountered, and use that knowledge whenever the modules are re-encountered. For example, speaking a credit card number in four chunks of four digits or speaking a North American telephone number in chunks of three, three, and four digits accelerates the dialog and makes the experience more natural for the caller. Most VoiceXML vendors have collections of dialog modules that, when reused, accelerate not only the callers' dialogs, but also the time to implement the application.