"mandatories" to take into account for a wide 32" touch screen interface?

Question

What are the best practices/"mandatory issues" to be taken into account and implemented on a 32" wide-aspect touch screen for a totem-kiosk application?

Especially appreciated issues on usability, accessibility, practical aspect regarding the specified target device, use cases.

EDIT:

• The specific project is a 3D immersive VT, there are object in the 3D space that can trigger the pop up of a window in which it is possible to interact with the represented object.

• This is intended for one person fruition, but it is likely that a group of curious ppl will expect looking ...

• It will be in landscape only mode

Answer 1

• Don't make anything too small to target accurately with a finger.
• Will the screen be only in portrait or landscape mode or does it have the potential for either mode?
• Will the user be demonstrating something to other users or will the application be for primarily one user? If viewed by a group, you may want to make the application interface larger; if only for an individual, you may make it smaller than you otherwise would.
• For a single user, it may be difficult to focus on everything at once on a screen that large. Any cause-and-effect changes should be blatantly obvious or should be localized to where the screen was touched if possible.
• Make it clear which gestures will accomplish what actions.

Answer 2

1. Consider the angle -- you say totem meaning it's 100% vertical, so keep interactions to short taps.
2. For example, don't rely on dragging -- in systems like this a user will quickly get tired of rubbing their finger across the screen (see the angle the user is holding their arm at, that looks tiring).
3. Consider using 3D sound as a guide in the 3D world (e.g. see this example in Google Earth
4. Wide-screen means tall-aspect items will be much smaller so bear this in mind. If you have documents, have 2 pages side by side for instance.
5. Consider low-cost eye tracking as a supporting gesture for navigation.
6. If the technology you're using is web-based, consider supporting multitouch

Answer 3

When (you know) the screen is as large as 32" and the user will be close enough to touch it, keep in mind that it may be difficult to interact with, or even notice, anything too far from the last item interacted with. You should consider physical proximity of UI elements much more than you normally would.