The cognitive dimensions framework is a broad-brush evaluation technique for interactive devices and for non-interactive notations. It sets out a small vocabulary of terms designed to capture the cognitively-relevant aspects of structure, and shows how they can be traded off against each other. The purpose of this paper is to propose the framework as an evaluation technique for visual programming environments. We apply it to two commercially-available dataflow languages (with further examples from other systems) and conclude that it is effective and insightful; other HCI-based evaluation techniques focus on different aspects and would make good complements. Insofar as the examples we used are representative, current VPLs are successful in achieving a good `closeness of match', but designers need to consider the `viscosity' (resistance to local change) and the `secondary notation' (possibility of conveying extra meaning by choice of layout, colour, etc.).

Since the early 1960’s, researchers have built a number of programming languages and environments with the intention of making programming accessible to a larger number of people. This article presents a taxonomy of languages and environments designed to make programming more accessible to novice programmers of all ages. The systems are organized by their primary goal, either to teach programming or to use programming to empower their users, and then, by each system’s authors ’ approach, to making learning to program easier for novice programmers. The article explains all categories in the taxonomy, provides a brief description of the systems in each category, and suggests some avenues for future work in novice programming environments and languages.

The effective use of visual languages requires a precise understanding of their meaning. Moreover, it is impossible to prove properties of visual languages like soundness of transformation rules or correctness results without having a formal language definition. Although this sounds obvious, it is surprising that only little work has been done about the semantics of visual languages, and even worse, there is no general framework available for the semantics specification of different visual languages. We present such a framework that is based on a rather general notion of abstract visual syntax. This framework allows a logical as well as a denotational approach to visual semantics, and it facilitates the formal reasoning about visual languages syntax and semantics for the visual languages VEX, Show and Tell, and Euler Circles. We demonstrate the semantics in action by proving a rule for visual reasoning with Euler Circles and by showing the correctness of a Show and Tell program.

Abstract. The rapidly developing field of diagrammatic knowledge representation and reasoning is surveyed. The origins and rationale of the field, basic principles and methodologies, as well as selected applications are discussed. Closely related areas, like visual languages, data presentation, and visualization are briefly introduced as well. Basic sources of material for further study are indicated. Key words: diagrammatic representation, diagrammatic reasoning, visual languages, diagrams, visual programming, data presentation, visualization, knowledge representation, computer graphics, qualitative physics, geometry theorem proving. 1.

I declare that this thesis is my own account of my research and contains as its main content work which has not previously been submitted for a degree at any tertiary education institution. Joel Kelso ii The purported advantages of Visual Programming, as applied to general purpose programming languages, have remained largely unfulfilled. The essence of this thesis is that functional programming languages have at least one natural visual representation, and that a useful programming environment can be based upon this representation. This thesis describes the implementation of a Visual Functional Programming Environment (VFPE). The programming environment has several significant features. • The environment includes a program editor that is inherently

a survey of programming environments and languages for novice programmers

The Cognitive Dimensions framework has inspired research both more and less varied than expected. In this paper we revisit the original aims and briefly describe some subsequent research, to consider whether the original aims were too austere in rejecting knowledge-based dimensions; whether the dimensions can be shown to have real-world relevance; and whether their definitions can be improved, either piecemeal or by refactoring the entire set. We mention some issues that remain unexplored, and conclude by describing two different ventures into defining clear procedures for real-life application, operating in very different milieux but both accepting that the framework should be developed from its original formulation. 2 1.

A powerful and useful Data-Flow Visual Programming Language (DFVPL) must provide the necessary programming constructs to deal with complex problems. The main purpose of this paper is to give a contribution to the debate on DFVPL constructs by presenting the solutions we devised for the VIPERS language. Another purpose of the paper is to illustrate the methodology we developed in order to start a comparative usability study for different implementations of control flow constructs. We stress the features of this original methodology, which is effective, easy to implement in different working contexts (even remote ones), and which gave us interesting clues about the way people inspect visual programs. 1. Introduction Data-flow is one of the most popular computational models for visual programming languages (VPL). One of the most important features which characterizes the power of a data-flow VPL and determines its acceptance is the availability of the rich library of predefined function...

The problem explored in this thesis is how to allow a person to map features from multiple video streams, or parts of those video streams, into an audio space, and how they can then monitor the resulting soundscape. I consider the requirements, user interface and architecture of a system that lets an end-user configure a video-only stream so that it generates an audio soundscape. In particular, I present a programming by demonstration environment called Cambience. Using this system, end users can map visual characteristics collected from video regions onto audio samples, and assemble the audio stream in a way that creates a meaningful soundscape. Cambience is used to mitigate a simple scenario between two distance separated collaborators and a shared resource. The wide range of visual programming elements allow for complex sonification behavior. Informal evaluations of the system show that Cambience has real usefulness with mostly minor considerations.- iii-Publications