Grizzly Bear: a demonstrational learning tool for a user interface specification language

Grizzly Bear is a new demonstrational tool for specifying user interface behavior. It can handle multiple application windows, dynamic object instantiation and deletion, changes to any object attribute, and operations on sets of objects. It enables designers to experiment with rubber-banding, deletion by dragging to a trashcan and many other interactive techniques. To the author’s best knowledge it is currently the most complete demonstrational user interface design tool that does not base its in ferencing on rule-based guessing. There are inherent limitations to the range of user interfaces that can ever be built by demonstration alone. Grizzly Bear is therefore designed to work hand-in-hand with a user interface specification language called the Elements, Events & Transitions model. As designers demonstrate behavior, they can watch Grizzly Bear incrementally build the corresponding textual specification, letting them learn the language on the fly. They can then apply their knowledge by modifying Grizzly Bear’s textual inferences, which reduces the need for repetitive demonstrations and provides an escape mechanism for behavior that cannot be demonstrated.