Why does Imagetalk look different?When designing the Imagetalk user interface, we had the common practices in symbol-assisted programs as a reference. But we also realized that the challenge of small-screen mobile devices and mobility features needed some new, innovative approaches. This explains why the Imagetalk user interface looks and behaves different compared to what may be expected from assistive communication programs. Let's look a bit closer to some findings we made and applied.
Let the symbols shine
The content represented as symbols-and-text is the user interface ingredient that should attract the attention of the user. Therefore we should avoid screen clutter and unmotivated use of colours in non-content. We did this by keeping the touch-screen function buttons neutral-color. They don't grab attention from the symbols. Also, we left out the grid in order to avoid screen clutter. Now you can visually and cognitively focus on the symbols and the according text.
This rule is absolutely not only about visual pleasure. It is very much a usability issue. Now, the user's attention is focused on the symbols. Leaving out the grid and other button area markings spontaneously direct our fingertip or touch-pen to the middle of the symbol. The actual selection area (the button area, if you like that expression) is bigger than the symbol itself. This functionality makes it easier to select the desired symbol.
Separate content from functions
Quite naturally, the grid concept so evident in traditional speech communicators was more or less directly taken as a basis for many symbols-based programs on PC. While placing content and functions freely in the dynamic grid is flexible and easy, it may provide cognitive confusion.
When designing the Imagetalk user interface, we decided to conceptually and visually separate functions, such as page navigation, message commands (send, save, etc.) and settings "outside" the content matrix. The program function buttons are not to be confused with the actual content symbols. Thus, we have always the basic functional buttons present on the screen, such as Mode and Menu.
The typical grid-based user interface has the obvious benefit, that you can include or exclude any functionalities -- provided that you remember to include the ones which you really need. The monolithic menu structure in Imagetalk has indeed been an obstacle. Not all users should access all functions, such as deleting a calendar message -- unintentionally or by purpose. We have now designed a two-level menu feature, which makes it possible to move menu items between the open and the pin-code protected menu. You as an administrator (you need to know the four-digit pin code) can reorganize all the menus as you like.
Use corners and edges
The small screen of the mobile device made us ask: how can we maximally utilize the screen estate? And to continue: how can a person with limited functional capabilities take advantage of the software on the small screen?
The answer was simple: we use corners and edges to visually "expand" the selection area "outside" the touch-screen, and to give the user tactile support from the screen edge. This way we could make the non-changing function button areas in corners and on edges substantially smaller than the content-related symbol areas, and still quite ergonomic through the support from the physical screen edge.
Avoid small objects
If you observe the user of a touch-screen pocket computer, he or she might start using the device with fingertip, but often has to finally grab the touch-pen in order to perform a scroll or some other fine-grained operation. This design flaw comes from migrating the mouse-operated user interface straight to the pocket computer environment.
One of the design objectives of Imagetalk has been to avoid small objects and operations, which require fine-motoric actions. One such is "free scrolling". We replaced that one with the page metaphor. Thus, you always navigate page up or page down, if you have more objects (such as messages in your inbox, or events in your calendar) than can be shown at once.
Notice that we don't say: avoid using the touch-pen. On the contrary, using the pen may give a user with limited functional capabilities an advantage by combining the "precise" pen with "generous" large-enough objects to point.
Be consistent, keep it simple
When designing software, even when you try to make it as intuitive and user-friendly as possible, you always have to implement some conventions. A good rule is to be consistent and to keep the amount of conventions, which the user has to learn and remember, as few as possible.
We have implemented consistency and simplicity with two-level touch-screen action. By pressing once, you perform basic operations, such as selecting a symbol to be included in your message. By keeping a symbol or button pressed until something happens, you perform an additional operation, such as getting more information. This two-level functionality has also been used to increase the user ergonomy so, that you have to keep mode and menu buttons pressed for a while in order to change mode or open the menu, thus avoiding unintentional selections.
Another example of consistency and simplicity is the similarity of different modes. When you learn how the message archive works, it is fairly easy to move over to the inbox. Even the calendar has a similar approach, of course with the difference, that calendar messages appear in time order.