Last month, researchers at MIT unveiled exciting new research developments in gestural interfaces at the TED conference in LongBeach (you can see the video here). In her presentation to the conference, Patti Maes (of MIT) demonstrates a device which reads visual information from the physical environment and uses a projector to create an interface along any surface. This interface is a touchable, interactive display which brings up information about (potentially) any physical item. Representing a quantum leap in the bridge between the physical and virtual worlds, this device has caused professionals and tech-geeks alike to created quite a media buzz. But is such a device more hype than delivery?

The user interface shown at TED is an impressive breakthrough in user interface technology; I do not question that. However, when the presentation emphasizes the point that the device could enter the market at an affordable price of $300 they liken themselves to Microsoft and Steven Spielberg who have visions of making this technology ubiquitous.

Does this device stand a chance of spreading throughout technology markets?

Consumer audiences have been fascinated with gestural interfaces ever since Tom Cruise manipulated a (not so) hyper-futuristic computer database with his fingers in the movie Minority Report. They have also been quick to adopt touch-screen interfaces, which have been integrated into bank tellers, check-out stands, and the ever-popular touchscreen mobile phone (iPhone).

However, they have also been quick to grow frustrated at such technology. Electronic signature pads continue to elude many people, and I am not the only person who grew frustrated at the iPhone touchpad keyboard. A similar technology to that unveiled at TED is the projection keyboard (pictured), which has been available for several years but remains unused and unadopted by the market.

My point of contention is this: the device like many other gestural interfaces provide no tactile feedback in using the device. Taking a cognitive psychologists point-of-view (ignoring all the privacy and moral issues of making technology ubiquitous for a moment), I believe this to be a crucial limitation to the device. I will state my bias here: I like my Android G1 smartphone much more than my iPhone because I make virtually no errors on the keypad where the iPhone touchpad was a consistent source of frustration. However, I still assert that this aspect of our cognitive apparatus is integral to human tool use. Can a tool be used effectively when it cannot be felt and grasped?

Our sense of causation and agency is rooted in tactile feedback. Humans are accustomed to a mode of acting in the world, where a physical state change (a key being clicked, a ball being pushed) creates some reaction. Many of these futuristic devices suffer from feedback issues inherent in a device the lacks this tactile mechanism. A user may move or make a gesture, interacting with the device, and perhaps nothing is registered and the state does not change. In these situations, people don’t know whether it is a limitation of their gesture (an incorrect input) or if the system is not configured or designed properly. Physical feedback removes ambiguity by acknowledging user input, putting the burden on the device. It can act as a reliable source of feedback for the user in any device.

There are many more questions regarding whether the market can bear another leap in user interface development. Let’s just say I have my skepticisms.