Daniel Avrahami (1,2), Jacob O. Wobbrock (2) and Shahram Izadi (3)
1 Intel 2 The Information School | DUB Group 3 Microsoft Research
2200 Mission College Blvd. University of Washington 7 J J Thomson Avenue
Santa Clara, CA 95054-1549 Seattle, WA 98195-2840 Cambridge, UK
Author Bios:
Daniel Avrahami
Jacob O. Wobbrock
- Senior researcher at Intel.
- Ph.D. and M.Sc. in Human-Computer Interaction from the HCI Institute (HCII) at the School of Computer Science (SCS) at Carnegie Mellon University (CMU).
Shahram Izadi
- Associate Professor in the Information School and an Adjunct Associate Professor in the Department of Computer Science & Engineering at the University of Washington.
- Ph.D. from the Human-Computer Interaction Institute in the School of Computer Science at Carnegie Mellon University.
- Research scientist at Microsoft Research Cambridge.
- Xerox PARC before that.
- PhD with Tom Rodden and Yvonne Rogers working on the EQUATOR project.
Summary:
They improved a tablet computer's tangible user interface (TUI) by attaching two cameras and software that can identify and track specific objects. They call it Portico because it extends the tablet's interactive possibilities without compromising the portability. In the picture, an application called Tabletgotchi is tracking a stuffed animal and can tell that it is "drinking" from the water displayed on the tablet's screen by registering its location and orientation from the raised cameras. The tablet can respond in a seemingly natural way to how the user moves the zebra.
Related work not referenced in the paper:
- Tangible Chess for the Compaq Tablet PC
- uses a tablet as a chess board. Each chess piece is tracked by contact with the touch screen where Portico uses cameras to track objects instead.
- Potentials of the Tangible User Interface (TUI) in Enhancing Inclusion of People with Special Needs in the ICT-Assisted Learning and e-Accessibility
- Explains how tangible user interfaces, such as Portico can be used to teach easily because of its natural way of interacting.
- TouchPlanVS Lite
- A Tablet-based Tangible Multitouch Planning System for Virtual TV Studio Productions - Uses a tablet to control an array of televisions and does not use cameras to track objects.
- The Tangible Pathfinder Design of a Wayfinding Trainer for the Visually Impaired
- It is theoretical in explaining how a virtual reality that uses tangible surfaces to help a visually impaired patient find their way around.
- Kolab: Appropriation & Improvisation in Mobile Tangible Collaborative Interaction
- A Microsoft Kinect camera is used to track objects on a flat surface. It differs from the Portico because it is completely reliant on the camera for input instead of using a tablet in conjunction with the camera.
- TUIC: Enabling Tangible Interaction on Capacitive Multi-touch Display
- An spatial tags are used on an iPad to register a location's position on the screen. Unlike Portico, it is restricted to the iPad's screen for interaction.
- Tangible Interaction in Mixed Reality Application
- Explains the importance TUI devices will have in the future and describes many examples, but none that I quickly read were exactly like Portico.
- Tangible Remote Controllers for Wall-Size Displays
- Uses a tablet to help users explore displays that are too large to see all at once such as a wall of screens. This is not the same idea as Portico.
- Tangible User Interface for Chemistry Education: Comparative Evaluation and Re-Design
- The authors of this paper hope that a TUI device could replace the ball and stick type models of chemicals to better teach students while keeping as much of the physical intuitiveness of the old way of teaching as possible.
- Tangible Bits: Beyond Pixels
- Explains contributions by the Tangible Media Group and others which do not appear to be similar to Portico.
All of these related work either show their idea for a TUI type design or talk about many ways that it can be used. They all have a unique idea about the subject and many of them even reference each other. All of the papers see TUI devices as a potentially huge teaching tool or a more natural way of design. Portico is a unique idea as I have not found anything similar in the papers above.
Evaluation:
They evaluated their work by creating a few applications that each use a different aspect of Portico for users to test. The applications were simple games that were tested informally by three children. A four year old and two three year olds. They used the qualitatively and subjectively observed how the children played with Portico to evaluate it. They took note of what the children had trouble with, what was not as intuitive as they had thought and their behavior as they played. The applications evaluated how Portico can track objects and then act accordingly to make the transition from the physical world and the virtual world as seamless as possible. They also subjectively observed that the range of the cameras could be increased to further its interactive surface. The only quantitative and objective evaluation taken was the frame rate of the cameras. They found that the cameras ran from 18 fps to 30 fps depending on the amount of objects in view of the cameras.
Discussion:
I believe that Portico is a step forward in TUI devices. There were no other papers I could find that went about using cameras and a tablet in a similar way. Many used tablets as a way to manipulate a larger display such as a TV instead of adding onto the tablet itself. Portico is absolutely a novel idea. The evaluation covered exactly what Portico was meant for and exposed some faults that they then explained solutions to.
