Showing papers by "Barbara Leporini published in 2008"

Applying Web Usability Criteria for Vision-Impaired Users: Does It Really Improve Task Performance?

Abstract: Available accessibility guidelines do not necessarily guarantee usable Web sites, particularly when specific groups of users with special needs are considered. We have identified 15 Web design criteria aiming to provide integrated support of accessibility and usability for vision-impaired users. In this article, we present the results of a study investigating whether the application of such guidelines for vision-impaired users can actually improve their task performance when accessing Web applications. We report on two user tests, both involving vision-impaired users, that aim to provide empirical validation of the design criteria. During each test, users had to access and navigate two versions of a Web site, one version supporting the selected design criteria and one obtained with traditional techniques. Our results indicate that the 15 design criteria improved Web site usability both quantitatively and qualitatively by reducing the navigation time needed to perform the assigned tasks and by making the W...

Vibrotactile feedback as an orientation aid for blind users of mobile guides

Abstract: In this paper, we present a solution for supporting vibrotactile feedback in mobile museum guides for blind users. To this end, we have designed and implemented a hardware/software module, which can be easily plugged into current PDAs to assist blind users in orientation. The solution, which comprises a two-channels haptic module as well as vocal support, has been exploited for moving through tagged objects. We also report on a user evaluation carried out with a number of blind users.

Supporting orientation for blind people using museum guides

Abstract: Novel environments exploiting recent technology can enhance several tasks in applications such as mobile guides. However, in the many museum mobile guides that have been proposed, accessibility is often not explicitly addressed and the benefits of such technology are rarely made available to blind users. In this paper, we propose a solution for flexible orientation support in a multimodal and location-aware museum guide, which has been developed specifically for blind users.

Evaluating a modified Google user interface via screen reader

Abstract: This paper describes the progress of a research project aimed at improving the usability of web search tools for blind users who interact via screen readers and voice synthesizers. In the first stage of research, specific guidelines were proposed for simplifying the interaction with search engines for the blind. To evaluate these criteria, they were applied to Google user interfaces, by re-implementing the search form as well as the results page. Finally, the redesigned interfaces were evaluated through remote testing with 12 totally blind users. The results highlighted how Google, although already accessible, may be further improved in order to simplify interaction for people with impaired vision.

Making Wikipedia editing easier for the blind

Abstract: A key feature of Web 2.0 is the possibility of sharing, creating and editing on-line content. This approach is increasingly used in learning environments to favor interaction and cooperation among students. These functions should be accessible as well as easy to use for all participants. Unfortunately accessibility and usability issues still exist for Web 2.0-based applications. For instance, Wikipedia presents many difficulties for the blind. In this paper we discuss a possible solution for simplifying the Wikipedia editing page when interacting via screen reader. Building an editing interface that conforms to W3C ARIA (Accessible Rich Internet Applications) recommendations would overcome accessibility and usability problems that prevent blind users from actively contributing to Wikipedia.

Is Wikipedia usable for the blind

Abstract: Today wikis are becoming increasingly widespread, and offer great benefits in a variety of collaborative environments. Therefore, to be universally valuable, wiki systems should be easy to use for anyone, regardless of ability. This paper describes obstacles that a blind user may encounter when interacting via screen reader with Wikipedia, and offers some suggestions for improving usability.

A Semi-automatic Support to Adapt E-Documents in an Accessible and Usable Format for Vision Impaired Users

Abstract: Electronic material (e-documents, e-books, on line resources, etc.) represents an essential tool for continuous learning for print-impaired people, provided it is well-structured. To obtain accessible and usable e-content, specific requirements should be applied from the early beginning or used when adapting existing electronic formats. In this paper we present a method, and a first associated prototype, for making e-documents in a format, which is accessible and usable for vision impaired users. The resulting environment is composed of various transformations, with different degree of automation, and applies a number of guidelines that have been defined for this purpose.

Making Conference CDs Accessible: A Practical Example

Abstract: The PDF document format is increasingly being used, including for conference CDs. This paper discusses the process of producing an accessible CD based on PDF documents for a small assistive technology conference, CVHI 07. It also analyses the accessibility features of the resulting PDF documents and the results of a survey of the conference authors on their experiences of (trying to) produce accessible PDF documents. The paper is introduced by brief discussions of PDF accessibility and of the results of surveys of the experiences of blind and visually impaired people of using PDF documents and the accessibility of PDF documents produced by UK universities. It concludes with a number of recommendations for conference organisers producing accessible CDs, as well as suggestions for future work.

Exploiting RFIDs and Tilt-Based Interaction for Mobile Museum Guides Accessible to Vision-Impaired Users

Abstract: In this paper, we present a study aiming to investigate how tilt-based interaction, along with RFIDs for localization, can be exploited to support blind users in interacting with mobile guides. We describe the design proposed and report on a first user study, which also compared two different ways to provide audio feedback (short sounds or vocal messages) for the tilt-based interaction.

"Fine Tuning" Image Accessibility for Museum Web Sites

Abstract: Accessibility and usability guidelines are available to design web sites accessible to blind users. However, the actual usability of accessible web pages varies depending on the type of information the user is dealing with. Museum web sites, including specimens and hall descriptions, need specific requirements to allow vision-impaired users, who navigate using a screen-reader, to access pieces of information that are mainly based on visual perception. Here we address a methodology to be applied for the proper creation and elaboration of alternative image descriptions in museum web pages. Such methodology has been applied to a gallery of the Museum of Natural History and Territory (University of Pisa). Such indications allow the user: (1) to address indexed contents and to link to information in more details, (2) to calibrate image descriptions (with a command providing alternative explanations for specimens), and (3) to access extra information for the blind (via hidden labels). A multidisciplinary approach is necessary to obtain effective and comprehensive descriptions. In this perspective, a cooperative environment is eventually proposed for team work facilitation.