Visual Support for the Isle Simulation Environment

INTRODUCTION All men by nature desire to know. An indication of this is the delight we take in our senses; for even apart from their usefulness they are loved for themselves; and above all others the sense of sight. For not only with a view to action, but even when we are not going to do anything, we prefer seeing to everything else. The reason is that this, most of all the senses, makes us know and brings many differences between things. Traditionally, the terms 'visual programming' and 'program visualization' have often been used interchangeably [10]. Recently, authors have been using these terms to distinguish different aspects of software engineering. For example, Myers [10] defines a visual programming system as " any system that allows the user to specify a program in two-(or more)-dimensional fashion ". He goes on to explain that traditional textual programs are not categorized as two dimensional because the compiler or interpreter treats them as a " long, one-dimensional stream ". On the other hand, Myers says that program visualization is " an entirely different concept ". Specifically, Myers states that, in program visualization " …the program is specified in the conventional, textual manner, and the graphics is used to illustrate some aspect of the program… " Therefore, according to Myers, program visualization only involves illustration of some aspects of an existing program (which may, itself, have been specified in a conventional textual language); whereas, visual programming involves development of a program using two or more dimensional graphical tools. 2 Other authors have made a similar distinction. For instance, Chang [3] says that the defining characteristic of visual programming is its " use of visual expressions in the process of programming " (as opposed to conventional, textual expressions). He clarifies visualization as the " use of visual representations to illustrate data, program, the structure of a complex system, or the dynamic behavior of a complex system. " Following Myers and Chang, we use the term program visualization to refer to any process of program manipulation and/or analysis that involves visualization. We reserve the term visual programming to refer to only those aspects of program development in which the user makes changes to a program using graphical tools. Moreover, we define the term visual support system as a computer system that supports both visual programming and program visualization. The present research involves a visual support system that …