Three Dimensional Software Modelling

Traditionally, diagrams used in software systems modelling have been two dimensional (2D). This is probably because graphical notations, such as those used in object-oriented and structured systems modelling, draw upon the topological graph metaphor, which, at its basic form, receives little benefit from three dimensional (3D) rendering. This paper presents a series of 3D graphical notations demonstrating effective use of the third dimension in modelling. This is done by e.g., connecting several graphs together, or in using the Z co-ordinate to show special kinds of edges. Each notation combines several familiar 2D diagrams, which can be reproduced from 2D projections of the 3D model. 3D models are useful even in the absence of a powerful graphical workstation: even 2D stereoscopic projections can expose more information than a plain planar diagram

Aesthetics of computation : unveiling the visual machine

Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2001."September 2001."Includes bibliographical references (p. 106-110).This thesis presents a new paradigm for the design of visual programming languages, with the goal of making computation visible and, in turn, more accessible. The Visual Machine Model emphasizes the need for clear visual representations of both machines and materials, and the importance of continuity. Five dynamic visual programming languages were designed and implemented according to the specification of the Visual Machine Model. In addition to individual analysis, a comparative evaluation of all five design experiments is conducted with respect to several ease of use metrics and Visual Machine qualities. While formal user tests have not been conducted, preliminary results from general user experiences indicate that being able to see and interact with computation does enhance the programming process.Jared Schiffman.S.M

Generalizing abstractions in form-based visual programming languages : from direct manipulation to static representation

We believe concreteness, direct manipulation and responsiveness in a visual programming language increase its usefulness. However, these characteristics present a challenge in generalizing programs for reuse, especially when concrete examples are used as one way of achieving concreteness. In this thesis, we present a technique to solve this problem by deriving generality automatically through the analysis of logical relationships among concrete program entities from the perspective of a particular computational goal. Use of this technique allows a fully general form-based program with reusable abstractions to be derived from one that was specified in terms of concrete examples and direct manipulation. Also addressed in this thesis is how to statically represent the generalized programs. In general, we address how to design better static representations. A weakness of many interactive visual programming languages is their static representations. Lack of an adequate static representation places a heavy cognitive burden on a VPL's programmers, because they must remember potentially long dynamic sequences of screen displays in order to understand a previously-written program. However, although this problem is widely acknowledged, research on how to design better static representations for interactive VPLs is still in its infancy. Building upon the cognitive dimensions developed for programming languages by cognitive psychologists Green and others, we have developed a set of concrete benchmarks for VPL designers to use when designing new static representations. These benchmarks provide design-time information that can be used to improve a VPL's static representation

A comparison of programming notations for a tertiary level introductory programming course

Increasing pressure from national government to improve throughput at South African tertiary education institutions presents challenges to educators of introductory programming courses. In response, educators must adopt effective methods and strategies that encourage novice programmers to be successful in such courses. An approach that seeks to increase and maintain satisfactory throughput is the modification of the teaching model in these courses by adjusting presentation techniques. This thesis investigates the effect of integrating an experimental iconic programming notation and associated development environment with existing conventional textual technological support in the teaching model of a tertiary level introductory programming course. The investigation compares the performance achievement of novice programmers using only conventional textual technological support with that of novice programmers using the integrated iconic and conventional textual technological support. In preparation for the investigation, interpretation of existing knowledge on the behaviour of novice programmers while learning to program results in a novel framework of eight novice programmer requirements for technological support in an introductory programming course. This framework is applied in the examination of existing categories of technological support as well as in the design of new technological support for novice programmers learning to program. It thus provides information for the selection of existing and the design of new introductory programming technological support. The findings of the investigation suggest strong evidence that performance achievement of novice programmers in a tertiary level introductory programming course improves significantly with the inclusion of iconic technological support in the teaching model. The benefits are particularly evident in the portion of the novice programmer population who have been identified as being at risk of being successful in the course. Novice programmers identified as being at risk perform substantially better when using iconic technological support concurrently with conventional textual technological support than their equals who use only the latter form. Considerably more at risk novice programmers using the integrated form of technological support are in fact successful in the introductory programming course when compared with their counterparts who use conventional textual technological support only. The contributions of this thesis address deficiencies existing in current documented research. These contributions are primarily apparent in a number of distinct areas, namely: • formalisation of a novel framework of novice programmer requirements for technological support in an introductory programming course; • application of the framework as a formal evaluation technique; • application of the framework in the design of a visual iconic programming notation and development environment; • enhancement of existing empirical evidence and experimental research methodology typically applied to studies in programming; as well as • a proposal for a modified introductory programming course teaching model. The thesis has effectively applied substantial existing research on the cognitive model of the novice programmer as well as that on experimental technological support. The increase of throughput to a recommended rate of 75 percent in the tertiary level introductory programming course at the University of Port Elizabeth is attributed solely to the incorporation of iconic technological support in the teaching model of the course

In Search of a Simple Visual Vocabulary

Visual languages are more complex than we would like. We introduce a small but powerful visual vocabulary for a visual programming environment that is simple, yet expressive enough to represent the structure of programs and program executions. This vocabulary is not based on any existing textual language. It was designed for the purpose of visually representing and understanding programs and their executions. I. Introduction V ISUAL languages are designed to make programming simpler by representing programming concepts visually. However, many researchers in the field concede that visual languages are still more complex than we would like. When the large collection of constructs that we use in textual programming is translated to a large collection of visual constructs for a visual language, textual complexity is merely replaced with visual complexity. Additional complexity arises when there is no clear relationship between visual symbols and the concepts they represent. Many visual..