What is Tangible Interface?

For my firts post with academic content I chose start from the basics : what is Tangible User Interface? (TUI).

I think a good start is talking about Graphical User Interface (GUI). A interface is something between the user and the system, a layer which has the function of integrate these human and machine. By the late 1990s almost all interfaces were GUI. The main characteristics of this interaction paradigm are: 

a) use of metaphors: a GUI usually imitates real objects and enviroments (like "Desktop", "Trash", etc);

b) a code of graphical signs called WIMP (Windows, Icons, Menus e Pointing devices).

The first personal GUI (Apple, 1983).

But in the end of 1990s new technologies, like Virtual and Augmented Reality, made possible overcome the WIMP model.

And, of course, finally I am talking about TUI. 

Certally a lot of people were working on something like TUI, but an official landmark for this new interaction paradigm is the work, in 1997, of Ullmer  (1). Ullmer proposed a classification of TUI into three types: interactive surfaces, built assemblies and assemblies made up of tokens and constraints. The basic components can be:

One of the first TUI

a) pyfos (a physical object that takes part in digital interaction. The term comes from the Spanish and was used to differentiate the common expression "object"); 

b) the token (one pyfo understandable, i.e., which can be captured by the digital part of the system and demonstrate virtual properties); 

c) constraints (one pyfo limiting behavior of the token which it is associated); and 

d) TAC, "token and constraints" (a relationship between tokens and constraints generating rules of interaction called "frames of references". rules of a TAC concerning how pyfos are coupled, relational definition between them, associations, interpretation what they do and computational rules of manipulation by the user).

OBS: There is others models beyond the Ulmer's TAC paradigm, but that is for another day, ok?

The main characteriscs of a TUI (2) are:

            space-multiplexing (the physical enviroment is changed by the inclusion of digital properties);

            concurrent access and manipulation (often involving twohanded interaction); 

            use of strong-specific devices (instead of weak-general, that is generic and non-iconic; 

            spatial awareness of the devices, and  spatial reconfigurability. 

Tomorrow I will talk about other characteristics of TUI. Specially about the cognitive issues involved  (Situaded Cognition is a fascinating field of Behavioral Sciences. Get ready!).

Now a video about TUi to end this post:

References

(1) - Ullmer, B. Tangible Interfaces for Manipulation Agregates of Digital Information. PhD Thesis, MIT, september of 2002.

(2) - Hornecker, E. Tangible Interaction. in : http://www.interaction-design.org/encyclopedia/tangible_interaction.html