next up previous
Next: Match Between the System Up: Usability Inspection Previous: Usability Inspection

Visibility of System Status

There is good visibility of system status. At the bottom of the main screen is a status bar which indicates the current mode of operation, such as draw mode or modify stroke groups mode. As the system is parsing formulae, it is possible to see the parser's current formula graph. This enables the user to see that it is working, and actually doing something.

When the user is entering symbols, the strokes are drawn in one colour. As they are completed and are waiting to be recognised, their colour changes. After recognition, their colour changes again and their bounding boxes are drawn. This display enables the user to know at all times what is happening with their strokes. When drawing in modify stroke groups, the line temporarily marked out by the pen is of a different colour to that drawn when entering symbols.

As the user changes between draw, modify stroke groups, modify character, and select and move modes, the mouse pointer changes to indicate the mode.

Steve Smithies