Tangible User Interface (TUI)

A tangible user interface (TUI) is a user interface in which a person interacts with digital information through the physical environment. The initial name was Graspable User Interface, which is no longer used. The purpose of TUI development is to empower collaboration, learning, and design by giving physical forms to digital information, thus taking advantage of human abilities of grasp and manipulate physical objects and materials.One of the pioneers in tangible user interfaces is Hiroshi Ishii, a professor in the MIT Media Laboratory who heads the Tangible Media Group. His particular vision for tangible UIs, called Tangible Bits, is to give physical form to digital information, making bits directly manipulable and perceptible. Tangible bits pursues the seamless coupling between physical objects and virtual data.

Characteristics

1. Physical representations are computationally coupled to underlying digital information.
2. Physical representations embody mechanisms for interactive control.
3. Physical representations are perceptually coupled to actively mediated digital representations.
4. Physical state of tangibles embodies key aspects of the digital state of a system

According to, five basic defining properties of tangible user interfaces are as follows:

1. space-multiplex both input and output;
2. concurrent access and manipulation of interface components;
3. strong specific devices;
4. spatially aware computational devices;
5. spatial re-configurability of devices.

Examples

A simple example of tangible UI is the computer mouse. Dragging the mouse over a flat surface and having a pointer moving on the screen accordingly. There is a very clear relationship about the behaviors shown by a system with the movements of a mouse.

Another example of a tangible UI is the Marble Answering Machine by Durrell Bishop (1992). A marble represents a single message left on the answering machine. Dropping a marble into a dish plays back the associated message or calls back the caller.

Another example is the Topobo system. The blocks in Topobo are like LEGO blocks which can be snapped together, but can also move by themselves using motorized components. A person can push, pull, and twist these blocks, and the blocks can memorize these movements and replay them.

Another implementation allows the user to sketch a picture on the system's table top with a real tangible pen. Using hand gestures, the user can clone the image and stretch it in the X and Y axes just as one would in a paint program. This system would integrate a video camera with a gesture recognition system.

Imagine having a computer system that fuses the physical environment with the digital realm to enable the recognition of real world objects. In Microsoft Pixelsense (formerly known as Surface), the interactive computing surface can recognize and identify objects that are placed onto the screen.

In Microsoft Surface 1.0, light from objects are reflected to multiple infrared cameras. This allows the system to capture and react to the items placed on the screen.