In Alex Iskold's article, The Rise of Contextual User Interfaces, the writer and CEO of software company AdaptiveBlue talks about the rise of contextual interfaces on the desktop an in the services we use on the web.
He points out the failing of choice over context in the old paradigm of UI design. Standardization of UI elements (tabs, combo boxes, etc.) was meant as a way to keep users from having to learn how to use an interface. The argument made was apparently that users are stupid and this paradigm supported the idea that we shouldn't innovate on core UI elements because users wouldn't be able to figure out how to user our applications. But over time UI designers simply made all of the choices available in an application in the forefront, putting the burden of having to sift through all of them.
Another philosophy of the old UI approach was that the user wants to see all information all the time. Instead of building UIs that responded to the way that people actually interacted with the tool, the user interface opened up all possible choices at all times. Naturally, this is completely overwhelming and confusing to people.
The result of the users are stupid/let's show all the choices paradigm ends up being, unfortunately, that even if users are smart enough to use these interfaces, they often end up feeling stupid when they can't figure out how to use bloated UIs. Sadly, many of these UIs make software so difficult to grok that we become frustrated using them, and often simply choose not use them.
The strategy of innovating interface elements based on usage and using simpler, contextual interfaces is the antithesis of the old paradigm, and is what is offered to rescue users from the flood of choices in lazily designed interfaces.
The new interfaces are winning people over because they are based on usage patterns instead of choices. The key thing about new UIs is that they are contextual - presenting the user with minimal components and then changing in reaction to user gestures. Thanks to Apple, we have seen a liberating movement towards simplistic, contextual interfaces.
Alex tells the story of something his boss once told him, declaring that user interface are cheap. What the boss meant was, that "the UI is so essential and so important to get right that you shouldn’t just reuse code and widgets."
Iskold points to Apple's ability to continually innovate on its interface, but points out that the use of contextual interfaces has increased on the web due to the use of the richer set of interactions provided by AJAX and RIA tools such as Flash. The example that many of us have commonly use are the controls provided by flash video sites when we hover over video players (e.g. in YouTube, Vimeo, etc.). These players hide the controls for viewing embedding options, related videos, etc. until you make the conscious decision to move the mouse over the video. Use of AJAX to make expert features available via expanding/collapsing and hiding/displaying design patterns are another example of contextual controls that can be provided nearby when needed.
Some of the innovations using contextual controls even break the traditional rules for how these controls work, but in the new model, this is done to provide emphasis to function over form. In the eyes of interface designers, the belief seems to be, "when an efficiency can be provided by breaking the rules, why not do it?"
http://alexiskold.wordpress.com/2008/05/15/the-rise-of-contextual-user-interfaces/