Text, graphics, and programs in the Boxer computational environment are stored in a hierarchy of nested boxes. In programs, boxes represent variables and procedures naturally and make their scope intuitive.
The Rationale Behind the Feature (Specific Design Principle):
Hierarchical organization is the principal method that people use to manage the complexity of large structures. Boxer makes it even easier to manage complexity by allowing boxes to be resized: They may be shrunk to hide their contents or expanded to fill the view and hide the higher levels of the hierarchy.
The spatial presentation of nested boxes is especially helpful for programming, because the entire state of a program is visible and accessible. The user is not required to maintain a mental model of the programs state.
Context of Use:
Boxes are the main organizing principle of the Boxer computational environment. Boxer may be used for general-purpose programming, to teach students to program, or to construct mini-worlds for teaching other subjects, such as math and physics. The box structure makes it easy to combine content from different sources: Just copy and paste the containing boxes into the new document.
Boxers designers originally provided a map utility to help users keep track of their locations in the hierarchy, but users had no difficulty navigating without it.
Boxer beginners tend to use good structure in their programs without being taught to do so, in contrast with the spaghetti code structures that beginning programmers often create in other languages.
Boxer users easily composed code by cutting and pasting boxes.
diSessa, A. A., Abelson, H., & Ploger, D. (1991). An Overview of Boxer. Journal of Mathematical Behavior, 10(1), 3-15.
diSessa, A. A. (1997), Twenty reasons why you should use Boxer (instead of Logo), in M. Turcsányi-Szabó (Ed.), Learning & Exploring with Logo: Proceedings of the Sixth European Logo Conference, Budapest Hungary, 7-27:
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