The construction of interactive software is known to be a difficult task. As far as the non-
interactive part of the application is concerned, designers can find support in the field of
software engineering, using object-oriented design methods for example. With regard to the
user interface per se, a number of interactive tools (interface builders) are available, that
allows creating interactively the look and feel of the interface. However, relating an object-
oriented design with a proper user-interface design is still a matter of craft and experience …