Abstract. Many developments have taken place within dataflow programming languages in the past decade. In particular, there has been a great deal of activity and advancement in the field of dataflow visual programming languages. The motivation for this article is to review the content of these recent developments and how they came

Large cooperative work systems require work coordination, context awareness and process modelling and enactment mechanisms to be effective. Support for process modelling and work coordination in such systems also needs to support informal aspects of work which are difficult to codify. Computer-Supported Cooperative Work (CSCW) facilities, such as inter-person communication and collaborative editing, also need to be well-integrated into both process-modelling tools and tools used to perform work. Serendipity is an environment which provides high-level, visual process modelling and event-handling languages, and diverse CSCW capabilities, and which can be integrated with a range of tools to coordinate cooperative work. This paper describes Serendipity's visual languages, support environment, and architecture, together with experience using the environment and integrating it with other environments. 1. Introduction Most computerised or semi-computerised work systems have evolved informal...

A weakness of many interactive visual programming languages (VPLs) 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.

ion John C. Grundy + and John G. Hosking ++ + Department of Computer Science University of Waikato Private Bag 3105, Hamilton, New Zealand jgrundy@cs.waikato.ac.nz ++ Department of Computer Science University of Auckland Private Bag 92019, Auckland, New Zealand john@cs.auckland.ac.nz Abstract We describe a visual language and environment for designing and implementing systems using the tool abstraction paradigm. This paradigm permits systems to be constructed from toolie and abstract data structure components, using an event response mechanism to handle inter-component interaction. This approach leads to systems more easily adapted to functional specification changes than with conventional design. 1. Introduction In a recent paper, Garlan et al [4] introduce the toolabstraction (TA) paradigm for constructing computer systems that support functional evolution. In this approach groups of abstract data structures (ADSs) are shared by a collection of co-operating toolies. Each toolie...

Component-based software architectures are increasingly being adopted as solutions for various software engineering problems. We describe a component-based software architecture and its supporting CASE tool we have been developing. Our tool supports both static and dynamic visualisation of component-based systems, together with end-user configuration of such systems by user extension of these visualisations. We describe the application of this tool to the development of component-based design environments, focusing on visualisations developed when specifying a process modelling tool. 1. Introduction Component-based software architectures are becoming more common as software developers realise these have greater potential for improved reusability, robustness and end-user configuration than conventional software systems. Example domains include user interfaces, databases, client-server architectures, design tools and visualisation tools. The central idea of component-based software arch...

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.

ion One of the challenges in visual programming research is scaling up to the support of ever-larger programs. This is a greater issue for VPLs than for traditional textual languages (although it certainly can be said to exist in both) for reasons relating to representation, language design and implementation, and relative youth of the area. For example, some of the visual mechanisms used to achieve characteristics such as explicitness can occupy a great deal of space, making it harder to maintain context. Also, it is hard to apply in a straightforward way techniques developed for traditional languages, because doing so often results in a reintroduction of the very complexities VPLs have tried to remove or simplify. Recent developments in the area of abstraction have been particularly important to the scalability of VPLs. The two most widely-supported types of abstraction, both in visual and textual languages, are procedural abstraction and data abstraction. In particular, procedural ...

This paper describes a new approach to visualizing program systems within the object-oriented paradigm. This approach is based on a T E X-like notation which has been extended and generalized for specifying graphical layout of arbitrary objects. The CLOS meta-level architecture is used to associate visualization and application objects. We propose several useful techniques such as indirect values, slot and method demons, and instance-specific metaobjects. Our techniques require no modifications to the systems which are selected for visualization. We demonstrate the feasibility of our approach using application domains such as CLOS debugging and constraint systems. 1 Introduction Although programming has mostly been done in textual terms users have always had a notion of visualizing their programs. Programs have been entered as lines of text but soon users started to indent their programs and also used comments for separating or emphasizing particular program parts. Tools were develop...

End-user programmers are writing an unprecedented number of programs, primarily using languages and environments that incorporate a number of interactive and visual programming techniques. To help these users debug these programs, we have developed an entirely visual, interactive approach to fault localization. This paper presents the approach. We also present the results of a think-aloud study that examined the interactive, human-centric issues that arise in end-user debugging using a fault localization strategy. Our results provide insights into the contributions such strategies can make to the end-user debugging process.

This paper describes the issues raised by the development of visual tools for the construction of graphical interfaces. It presents Whizz'Ed, an experimental editor for construction of highly interactive or animated applications. In addition to the features of traditional interface builders, Whizz'Ed makes it possible to visually describe by direct manipulation the behaviour of graphical objects and their interrelations. Whizz'Ed encapsulates basic behaviours in elementary bricks that can be connected using a data-flow model. The flow graph can be structured in order to reuse complex behaviours, thus allowing the designer to create new reusable bricks at design time.