Designing Voice User Interfaces

Chapter 5. Advanced Voice User Interface Design

IN Chapter 2, WE went over voice user interface (VUI) design basics. In this chapter, we cover topics related to making your VUI not merely functional and usable, but beyond. Here, we take a look at what will make it most engaging, easy to use, and successful.

Siri and the Amazon Echo are both examples of popular VUIs. The Echo has recently received a lot of praise about its interface. Given that the two systems can do many similar things, why is the Echo often a better user experience? One reason is that the Echo was designed with voice in mind from the beginning—that’s its sole purpose. Siri, by comparison, is just one more way to interact with your iPhone.

As Kathryn Whitenton writes: “The Echo, on the other hand, prioritizes voice interaction above all else.” She goes on:

Siri’s ability to expedite web searches with voice input for queries is certainly valuable, but the bias toward interpreting user questions as web searches can actually increase error rates when doing other tasks. The benefit of the Echo’s more focused functionality is even more apparent if you need multiple timers (not an uncommon scenario when cooking). When asked to set a new timer, Alexa easily responds, “Second timer set for 40 minutes, starting now,” while Siri, which only has one timer, balks: “Your timer’s already running, at 9 minutes and 42 seconds. Would you like to change it?

But for short tasks, failing to hear a command the first time can easily tip ...