Paper Reading #22: Mid-air Pan-and-Zoom on Wall-sized Displays

Mathieu Nancel is a PhD student of HCI at the University of Paris
Julie Wagner is a postgraduate research student at the University of Paris.
Emmanuel Pietriga is a full-time research assistant at the University of Paris.
Olivier Chapuis is a research scientist at University of Paris.
Wendy Mackay is the research director at INRIA. 


This paper was presented at CHI 2011.


Summary
Hypothesis
In this paper, researchers experimented with various ways to control a wall-sized display. They had several hypotheses regarding which ways would be preferred. They believed that two handed gestures will be faster and easier to use than one-handed gestures. They also believed that users will prefer circular gestures. They predicted that small gestures would be preferred.

Methods
In the project, researchers tested various different types of gestures. First, they used uni-manual (one handed input) and bi-manual (two handed input). Each of these manual gestures could be used in conjunction with 1D control, 2D surface, and 3D free space.
The 1D control was control in one plane using a linear scrollwheel or a circular scrollwheel.
The 2D surface was control using a PDA or smartphone.
The 3D free space allowed gestures to be used.
With the bi-manual input, one hand was used to show the focus of the gesture, i.e. where to focus the zoom or pan, etc.

In the experiment, the researchers tested three factors: Handedness (one handed, two handed), Gesture (circular, linear), and guidance (1D, 2D, 3D).

Each participant was given a target in a high zoom scale. They had to zoom out to display all targets and they had to pan the targets so they were all visible on the screen.

Results
In most cases, they found that two hands (bimanual gestures) were faster and had shorter movement times
They also found that 1D path control was much faster than the other input types.
Linear control was also found to be faster than circular.

In the qualitative results, participants seemed to prefer the one handed gestures. They also preferred the linear gestures to circular gestures. They found that circular gestures on a surface were too hard to do.

Discussion
The paper itself was fairly interesting although it was slightly difficult to identify with since I've never personally used a large wall-sized display. I wasn't able to really agree or disagree with their findings since I've never had to use gestures on such a large display.

This kind of research could potentially become very helpful in the future when wall-sized displays become more widely used, though. Another user qualitative might be helpful in the future as well. By letting users design their own gestures, they could choose the most natural gestures for the large wall.