It may seem to us now that voice user interfaces (VUIs) aren’t learning quickly enough, but they’re actually evolving at a pretty good pace. Primary platforms are making substantial strides to define the process and practice of crafting a VUI, for example, so that third-party UX designers can bring us new and hopefully better experiences. But UX designers also need time to adapt. Yes, they can follow many of the fundamental guidelines they’re used to applying to visual interfaces, but they also need to operate with new tools and new rules. What makes VUI most difficult is the absence of a visible interface — there are no confines of a screen to keep users boxed in. In this space, we have to design for every possible situation without that visible safety net.
https://venturebeat.com/2018/07/28/conversation-design-the-right-approach-to-crafting-voice-interfaces/
