Summary of Data Structure Visualization and Open Problems

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Summary and Open Problems

Although the systems summarized in this paper have shown the promise that data structure visualization holds, data structure display systems still are not widely used in teaching and still are not commonly included in IDEs for programmers to use. Until data structure display systems achieve more general acceptance, the area will continue to exhibit unfulfilled potential. Anyone who has ever programmed will surely agree that a visualization of the complex interactions of data can only help comprehension and debugging of computer programs. Now that software and hardware improvements for graphical displays have made these types of visualizations routine, hopefully, this unfulfilled potential will be reached. Below we describe some specific problems that remain to be solved in order to help foster the growth of data structure visualization.

• User-defined displays – Invariably, advanced programmers or programmers in a specific application area will want to build customized views of particular data types and structures. Existing systems have only either provided generic default displays or have required people to do tedious graphical design in order to build custom views. A powerful data structure display system should allow users to quickly and easily demonstrate a new graphical form for a data structure. Thus, a data structure display system likely must include some form of sophisticated graphical editor or toolkit to facilitate view design.

• Mapping data to their display – In addition to designing new views, designers must be able to specify how data is to be interpreted to generate the views. Creating an easy-to-understand and easy-to-use mapping scheme is quite difficult, particularly if multiple pieces of data can “drive” a particular view or one piece of data can be presented in different view abstractions.

• Complex, large data – With the possible exception of DDD, prior data structure display systems have been better suited for programming-in-the-small with relatively straightforward, moderate-sized data structures. Sophisticated display imagery becomes significantly more difficult as the complexity and sheer size of the data increases, thereby complicating screen layout issues. Further abstraction and mapping strategies are required to properly address these issues also.

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