Maintaining Screen Space
Tabstrip | "Switchable Areas" | Screen Changes | Do Not...
As touchscreens usually are of fixed and relatively small size (640*480 or 800*600 pixels) and screen element have to be large enough to be operable by fingers, screen space is at premium with touchscreens. Here are some proposals for overcoming the space limitations of touchscreens.
Tabstrip
A tabstrip can be used to virtually enlarge a screen by providing a device that enables the users to switch between different views.
A tabstrip consists of a "tab area" which contains buttons for switching the view, and of a "presentation area" which is usually of fixed size (it may be scrollable) and displays the different views.
The buttons allow to access to views in random order.
"Switchable Areas"
A similar technique consists in assigning certain screens areas to fixed functions like data display, function key area, keypad area etc. Pushbuttons can be used to exchange to elements in such a fixed area, for instance to switch between
- different list views
- different versions of a keypad
- different button sets or groups
Screen Changes
Users may navigate between screens which, for instance, provide access to different components of a compound data object. However, this technique may provide problems for nonprofessional users - they may loose orientation and may have problems processing their tasks. Therefore,
- give the screens a consistent layout and look, so that users perceive them as a unity
- make clear which the navigational options are, e.g. how users can proceed and backtrack
- limit he number of screen changes to a small number
Do Not...
- Do not make the screen scrollable like long dynpros in R/3 or HTML pages!!!
- Do not use a multiple-window interface as Windows or Mac OS have!!!
topSource: Interaction Design Guide for Touchscreen Applications