Rachel Hinman argues that successful PC and mobile experiences are built on fundamentally different conceptual models and leverage different psychological functions of the user. Understanding these differences will help you create better experiences for both contexts.

Users of desktop experiences interact with graphical user interfaces (aka GUIs). Graphical user interfaces are built on the psychological function of recognition. Users click on a menu item, the interface provides a list of actions, the user recognizes the appropriate action and clicks on it. GUIs reliance on recognition gave rise to the term WYSIWYG (What you see is what you get). Users can see all their options and minimal visual differentiation between interface elements is commonly used.

In contrast, mobile experiences - especially those with touch screens and natural user interfaces - can feel anchorless by comparison....

The natural user interfaces (aka NUIs) found on most modern mobile devices are built on the psychological function of intuition. Instead of recognizing an action from a list, users must be able to sense from the presentation of the interface what is possible. Instead of "what you see is what you get" NUIs are about "what you do is what you get." Users see their way through GUI experiences, and sense their way through NUI ones. Unlike GUI interfaces with minimal differentiation between interface elements, NUI interfaces typically have fewer options and there is more visual differentiation and hierarchy between the interface elements.

Read her complete article here. Via Putting People First.