The aim of a natural user interface is to have an intuitive and organic interaction between user and technology, with absolute deference to simplicity.
Consider the following when designing a natural user interface:
- NUI applications must be designed for zero learning curve. Take a kiosk in an airport or a learning station in a museum. The interface must be so simple a person who has never seen it before is using the technology in less than 5 seconds.
- Provide learnable gestures for shortcuts. A great example of this is the copy/paste feature available in iOS3.
- Think about ways to leverage passive inputs such as a camera that observes the user's behaviors or GPS location identification for applications designed around locations.
- Plan for offline situations when Internet connectivity is not available or signals are low. Even if your app uses connected data think about how you can keep users from being dead in the water if the connection is broken. In a kiosk application we knew had a very high risk of being disconnected, we implemented local storage for all content and a periodic check for new information.
- Develop parallelisms with your website. Like most users, I switch from my iPad app to a company's website frequently. The good applications make this easy by using equivalent labels and functionality. They also link directly from an app to the equivalent page on their website. However, do NOT duplicate your website in your tablet app.