Natural user interface

In computing, a natural user interface (NUI) or natural interface is a user interface that is effectively invisible, and remains invisible as the user continuously learns increasingly complex interactions. The word "natural" is used because most computer interfaces use artificial control devices whose operation has to be learned. Examples include voice assistants, such as Alexa and Siri, touch and multitouch interactions on today's mobile phones and tablets, but also touch interfaces invisibly integrated into the textiles of furniture.

An NUI relies on a user being able to quickly transition from novice to expert. While the interface requires learning, that learning is eased through design which gives the user the feeling that they are instantly and continuously successful. Thus, "natural" refers to a goal in the user experience – that the interaction comes naturally, while interacting with the technology, rather than that the interface itself is natural. This is contrasted with the idea of an intuitive interface, referring to one that can be used without previous learning.

Several design strategies have been proposed which have met this goal to varying degrees of success. One strategy is the use of a "reality user interface" ("RUI"), also known as "reality-based interfaces" (RBI) methods. One example of an RUI strategy is to use a wearable computer to render real-world objects "clickable", i.e.