What are tangible user interfaces?

During the last few days, I’ve been doing a lot of internet surfing at the office in search for good examples of trends in user interface (UI) design for one of our award winning 360 Trend Reports.

On it’s on, that is already quite a daunting task, as there are so many things out there that it’s difficult to pick and filter everything out. To top it off, there seem to be a lot of overlapping terms to define different types of interfaces which doesn’t make it any easier when you try to organize and classify them.

But anyway, going straight to the point, one of the most interesting user interface paradigms I’ve come across not only during my search but also during my studies, is the Tangible User Interface (TUI), so I decided to dedicate this post to explaining what they are and to show a few great examples of (soon to be) products which make use of this type of interaction.

To start up, here’s my definition:

A tangible user interface is one in which the user interacts with a digital system through the manipulation of physical objects linked to and directly representing a quality of said system.

The idea with TUIs is to have a direct link between the system and the way you control it through physical manipulations by having an underlying meaning or direct relationship which connects the physical manipulations to the behaviours which they trigger on the system.

And I think that in this last statement is where the secret lies. It’s not just a question of having a physical controller for your digital system for the sake of having one, but making sure that by implementing one, it’s use makes sense to the user and has added value for a more natural and intuitive control of your design. In a sense, the interface becomes virtually invisible, as the user has an inherent knowledge of manipulations such as grasping and moving objects (after all, we’ve been practising since we were toddlers) so he is able to concentrate more on the system and the triggered behaviours than on how to trigger them.

Great examples of Tangible User Interfaces

The good ol’ mouse

It could be argued that one of the earliest examples of a tangible user interface is the all-too-well-known mouse.

Dragging a mouse through a flat surface and having a pointer move on a screen accordingly is a very straight forward way of interacting with a digital system through the manipulation of a physical object and the movements made with the device have a clear relationship with the behaviours which are triggered on the system (e.g. pointer moves up when you move the mouse forward), making it a very easy to master input device (with the help of a bit of hand-eye coordination). Its development was definitely one of the key factors which helped bring personal computing to the masses.

Siftables

My favourite example of TUIs is by far the Siftables. These small devices, which started as a project at the MIT Media Lab and which are soon to make the jump into commercially available products, are in essence tiny intelligent bricks with a display on them which are able to communicate and interact with each other depending on their position. The separate bricks know when another brick is near to them and depending on the game you are playing, they react accordingly.

I could go on and on about them, but as always, there’s people out there who’ve done the job so well before so why try to re-invent the wheel? just take a look at the couple of demos shown on the videos below and head over to www.sifteo.com for the nitty-gritty.

Reactable

Reactable is a musical instrument designed with state of the art technology in order to allow musicians (and others) to experiment with sounds and create unique music.

The instrument is based on a translucent and luminous round table in which a set of pucks can be placed. By placing them on the surface (or taking them away), by turning them and connecting them to each other, performers can combine different elements like synthesizers, effects, sample loops or control elements in order to create a unique and flexible composition.

As soon as any puck is placed on the surface, it is illuminated and starts to interact with the other neighboring pucks, according to their positions and proximity. These interactions are visible on the table surface which acts as a screen, giving instant feedback about what is currently going on in the Reactable, turning music into something visible and tangible.

Microsoft Surface

Microsoft Surface is a table-like all-in-one computer, with a multi touch display which allows multiple users to interact with the built in system at the same time. But what really concerns us here is that it reacts not only to touch, but can also recognize objects placed on top of it and trigger it’s own set of behaviours linked to these objects and how you manipulate them.

And although the video below doesn’t explore much of the real possibilities of having this tangible interaction with Surface through objects (it merely shows info relevant to the object they place on top), you can check another video on the official site where a bit more of this interaction with objects is showcased (look for the one called “Surface and Objects”).

Snippets from other products

Some other products have introduced a bit of the essence of tangible user interfaces into controlling some features of their systems by combining them with so called gestures such as tilting or shaking an object (we saw an example of this also with the paint cans example of Siftables above).

A very nice example from products currently available on the market is the idea of shaking your iPod to shuffle the music. I love this example especially because of the direct meaning attributed to shaking an object (like for example a juice box) and how it is directly connected to the action it is performing (mixing the content) which is exactly what I mentioned before about the interface making sense and having a connection to the inherent knowledge of the user to make the interface seam invisible.

Some interesting places to visit

So that’s about it from me just to give you a flavour of TUIs, but if you are interested in tangible user interfaces (and if you landed here I’m gonna go right ahead and guess you are), you might wanna take a look at the following websites which can shed a bit more light into what’s behind them and give you a taste of some more (experimental) examples.

And for the Do It Yourself people out there…

Phidgets

Phidgets are a great set of plug-and-play sensors and actuators that you can use to create your own prototypes of tangible interfaces. With a very nice and complete collection of devices such as accelerometers, distance and motion sensors, LEDs, motors, etc, wich when connected to your PC and with bit of coding (a lot of different languages are supported) they are very easy to use building blocks for interaction designers wanting to experiment with physical user interfaces.

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