Although detractors of functional programming sometimes claim that functional programming is too difficult or counterintuitive for most programmers to understand and use, evidence to the contrary can be found by looking at the popularity of spreadsheets. The spreadsheet paradigm, a first-order subset of the functional programming paradigm, has found wide acceptance among both programmers and end users. Still, there are many limitations with most spreadsheet systems.

In the past, attempts to extend the spreadsheet paradigm to support graphical objects, such as colored circles or user-defined graphical types, have led to approaches featuring either a direct way of creating objects graphically or strong compatibility with the spreadsheet paradigm, but not both. This inability to conveniently go beyond numbers and strings without straying outside the spreadsheet paradigm has been a limiting factor in the applicability of spreadsheet languages. In this paper we present graphical definitions, an approach that removes this limitation, allowing both simple and complex graphical objects to be programmed directly using direct manipulation and gestures, in a manner that fits seamlessly within the spreadsheet paradigm. We also describe an empirical study, in which subjects programmed such objects faster and with fewer errors using this approach than when using a traditional approach to formula specification. Because the approach is expressive enough to be used with both built-in and user-defined types, it allows the directness of demonstrational and spreadsheet techniques to be used in programming a wider range of applications than has been possible before.

Rights to individual papers remain with the author or the author's employer. Permission is granted for noncommercial reproduction of the work for educational or research purposes. This copyright notice must be included in the reproduced paper. USENIX acknowledges all trademarks herein.

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 ...

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.

End-user programmers develop more software than any other group of programmers, using software authoring devices such as multimedia simulation builders, e-mail filtering editors, by-demonstration macro builders, and spreadsheet environments. Despite this, there has been only a little research on finding ways to help these programmers with the dependability of the software they create. We have been working to address this problem in several ways, one of which includes supporting end-user debugging activities through interactive fault localization techniques. This article investigates fault localization techniques in the spreadsheet domain, the most common type of end-user programming environment. We investigate a technique previously described in the research literature, and two new techniques. We present the results of an empirical study to examine the impact of two individual factors on the effectiveness of fault localization techniques. Our results reveal several insights into the contributions such techniques can make to the end-user debugging process, and highlight key issues of interest to researchers and practitioners who may design and evaluate future fault localization techniques.

End users develop more software than any other group of programmers, using software authoring devices such as e-mail filtering editors, by-demonstration macro builders, and spreadsheet environments. Despite this, there has been only a little research on finding ways to help these programmers with the dependability of the software they create. We have been working to address this problem in several ways, one of which includes supporting end-user debugging activities through interactive fault localization techniques. This thesis investigates these fault localization techniques in the realm of end-user programming. We investigate a technique previously described in the research literature, and two new techniques that are introduced in this thesis. This thesis also presents the results of two empirical studies to examine whether fault localization techniques are effective in end-user testing and debugging tasks. The first study compares how well the three techniques isolate the faults in two end-user programs. The second study examines the impact of two orthogonal factors on the effectiveness of fault localization techniques. Our results reveal several insights into the contributions such techniques can make to the end-user debugging process, and highlight key issues of interest to researchers and practitioners who may design and evaluate future fault localization techniques. CHAPTER 1