Thursday, February 23, 2012

Experiences with and Observations of Direct-Touch Tabletops


This paper goes over the user experiences of direct-touch tabletops. They go into details about aspects such as simultaneous touching, ambiguous input, one-fingered touch, finger resolution, alternate touch input, crowding and clutter, text input, orientation, multi-user coordination, occlusion, ergonomic issues, and mental models. The system used for their experiences and observations is DiamondTouch, which is a direct multi-touch, multi-user table top that also offers the utility of identifying which user is touching which particular location on the surface.


An observation they made about simultaneous touching was that users hesitated to use table top at the same time as others. This is most likely because user’s are unfamiliar with the shared work space, but the pro is that users will accept it over time.

Another observation they made was about ambiguous touches. User’s simple accidentally touched the table with their wrists, etc...

User’s started off by only using one finger to interact with the devices. However, after some video learning & use of the system, the users began to interact with the device with multiple fingers and hands.

There is some cognitive friction occurring with users finger resolution. User’s have different size fingers, touching with a finger is not as precise as touching with a mouse, and standard windows, etc... are targeted towards a pointer from a mouse rather than a finger. A designer would have to keep this in mind when creating a UI for a multi-touch system. Rather than using standard UI elements found on a traditional computer, UI elements must be different when the user is interacting with the system with a multi-touch rather than a mouse.

Some users preferred to use a stylus or some other abstracted input device. The pro of directly interacting with the system is that there is no extra layer of abstraction and when using the stylus, that layer of abstraction is not gone.

Users preferred to have their “space” when using the system. For multi-user systems, there must be a certain amount of space for the user’s to feel comfortable, but be close enough so user’s can simultaneously “work” together. User’s shouldn’t be close enough as to accidentally touch an object that another user is interacting with.

User’s showed problems when trying to enter text into the machine. An external “real” keyboard should be available for users.

There were little problems found with orientation for small chunks of text but had trouble large chunks of text. They were hesitant to use the mechanism to rotate the text. In the paper, several solutions were proposed to address this issue where each solution might be best for a specific application of use.

Users had problems coordinating with each other either by accident or intentionally. Mechanisms for coordination are cited in the paper.

They noticed that occlusion or shadows from hands for top projection devices showed almost no problems for users.

The physical design of the system such as width & height showed some problems because user’s would accidentally trigger unintended input to the system. They showed that a low (coffee table) surface is better for casual tasks while a higher (desk) surface is better for productivity tasks.

Finally, they found that the users did not view the interactive table top as a computer. This was a pro since users found it more pleasant to use than a traditional desktop computer.

  • DiamondTouch’s ability of identifying which user is touching particular location on the surface.
  • Some problems are just because users are unfamiliar with touch surfaces and it will become more “natural” once it is more commonly used.
  • Touch as a standard input that should be taught to children in a basic computer learning course such as a mouse, keyboard, stylus, etc...

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