Calvin B. Swart

Bio: Calvin B. Swart is an academic researcher from IBM. The author has contributed to research in topics: User interface & Information foraging. The author has an hindex of 11, co-authored 35 publications receiving 443 citations.

Look-up table based gamma and inverse gamma correction for high-resolution frame buffers

Abstract: An image display system includes an input to a source (10, 12, 14) of image pixel data wherein each pixel is expressed as an M-bit value within a non-linear range of values. A first LUT (16) is coupled to an output of the source for converting each M-bit pixel value to an N-bit value within a linear range of values. An image memory, or frame buffer (18), has an input coupled to an output of the first LUT for storing the N-bit pixel values. The system further includes a second LUT (20) coupled to an output of the frame buffer for converting N-bit pixel values output by the frame buffer to P-bit pixel values within a non-linear range of values. The converted values are subsequently applied to a display (24). In an exemplary embodiment, the first LUT stores gamma corrected pixel values and the second LUT stores inverse gamma corrected pixel values. Preferably the second LUT stores a plurality of sets of inverse gamma corrected pixel values. Also, the frame buffer stores, for each of the N-bit pixel values, a value that specifies a particular one of the plurality of sets of inverse gamma corrected pixel values for use in converting an associated one of the N-bit pixel values.

Improving web accessibility through an enhanced open-source browser

Abstract: The accessibilityWorks project provides software enhancements to the MozillaTM, Web browser and allows users to control their browsing environment. Although Web accessibility standards specify markup that must be incorporated for Web pages to be accessible, these standards do not ensure a good experience for all Web users. This paper discusses user controls that facilitate a number of adaptations that can greatly increase the usability of Web pages for a diverse population of users. In addition to transformations that change page presentation, innovations are discussed that enable mouse and keyboard input correction as well as vision-based control for users unable to use their hands for computer input.

Reactive information foraging: an empirical investigation of theory-based recommender systems for programmers

Abstract: Information Foraging Theory (IFT) has established itself as an important theory to explain how people seek information, but most work has focused more on the theory itself than on how best to apply it. In this paper, we investigate how to apply a reactive variant of IFT (Reactive IFT) to design IFT-based tools, with a special focus on such tools for ill-structured problems. Toward this end, we designed and implemented a variety of recommender algorithms to empirically investigate how to help people with the ill-structured problem of finding where to look for information while debugging source code. We varied the algorithms based on scent type supported (words alone vs. words + code structure), and based on use of foraging momentum to estimate rapidity of foragers' goal changes. Our empirical results showed that (1) using both words and code structure significantly improved the ability of the algorithms to recommend where software developers should look for information; (2) participants used recommendations to discover new places in the code and also as shortcuts to navigate to known places; and (3) low-momentum recommendations were significantly more useful than high-momentum recommendations, suggesting rapid and numerous goal changes in this type of setting. Overall, our contributions include two new recommendation algorithms, empirical evidence about when and why participants found IFT-based recommendations useful, and implications for the design of tools based on Reactive IFT.

Reactive information foraging for evolving goals

Abstract: Information foraging models have predicted the navigation paths of people browsing the web and (more recently) of programmers while debugging, but these models do not explicitly model users' goals evolving over time. We present a new information foraging model called PFIS2 that does model information seeking with potentially evolving goals. We then evaluated variants of this model in a field study that analyzed programmers' daily navigations over a seven-month period. Our results were that PFIS2 predicted users' navigation remarkably well, even though the goals of navigation, and even the information landscape itself, were changing markedly during the pursuit of information.

Designing an E-grocery application for a palm computer: usability and interface issues

Abstract: The coming ubiquity of handheld devices and e-commerce will offer many new design and application opportunities for human-computer interaction, many of them in "everyday" domains. This article reports on the iterative design of a handheld application for one such domain, grocery shopping. Our goal was to produce a solution for home ordering of groceries using a PDA. The article focuses on the evolution of the application design through a process that alternated design activities with formative evaluations in the field. At the end of the design and development process, 200 shoppers in the United Kingdom were using the resulting application.

Universal access in the information society

Abstract: ▶ Addresses the accessibility, usability, and, ultimately, acceptability of Information Society Technologies by anyone, anywhere, at anytime, and through any media and device. ▶ Focuses on theoretical, methodological, and empirical research, of both technological and non-technological nature. ▶ Features papers that report on theories, methods, tools, empirical results, reviews, case studies, and best-practice examples.

Free/Libre open-source software development: What we know and what we do not know

Abstract: We review the empirical research on Free/Libre and Open-Source Software (FLOSS) development and assess the state of the literature. We develop a framework for organizing the literature based on the input-mediator-output-input (IMOI) model from the small groups literature. We present a quantitative summary of articles selected for the review and then discuss findings of this literature categorized into issues pertaining to inputs (e.g., member characteristics, technology use, and project characteristics), processes (software development practices, social processes, and firm involvement practices), emergent states (e.g., social states and task-related states), and outputs (e.g. team performance, FLOSS implementation, and project evolution). Based on this review, we suggest topics for future research, as well as identify methodological and theoretical issues for future inquiry in this area, including issues relating to sampling and the need for more longitudinal studies.

Automatic summarising: The state of the art

Abstract: This paper reviews research on automatic summarising in the last decade. This work has grown, stimulated by technology and by evaluation programmes. The paper uses several frameworks to organise the review, for summarising itself, for the factors affecting summarising, for systems, and for evaluation. The review examines the evaluation strategies applied to summarising, the issues they raise, and the major programmes. It considers the input, purpose and output factors investigated in recent summarising research, and discusses the classes of strategy, extractive and non-extractive, that have been explored, illustrating the range of systems built. The conclusions drawn are that automatic summarisation has made valuable progress, with useful applications, better evaluation, and more task understanding. But summarising systems are still poorly motivated in relation to the factors affecting them, and evaluation needs taking much further to engage with the purposes summaries are intended to serve and the contexts in which they are used.

Systems and methods for controlling illumination sources

Abstract: Provided are methods and systems for controlling the conversion of data inputs to a computer-based light system into lighting control signals. The methods and systems include facilities for controlling a nonlinear relationship between data inputs and lighting control signal ouputs. The nonlinear relationship may be programmed to account for varying responses of the viewer of a light source to different light source intensities.

Graphic user interface for a digital content delivery system using circular menus

Abstract: Menu structures having a balanced, predominantly circular appearance for a graphic user interface (GUI) for a delivery system of multiple categories of digital information content. The menu has two concentric rings having icons arranged along the rings identifying menu choices. The outer menu ring presents choices of categories of digital contents available from the content delivery system, while the inner menu ring presents choices of sub-categories of contents associated with a category. The icons are individually selectable. The categories and subcategories displayed are dynamically determined based on the content available to the user. The GUI system allows a user to select a category and sub-category of digital contents by selecting an icon from the outer and inner menu ring, respectively. In response to each selection, the GUI generates animated effects on the graphic display to highlight the selected item.