Assisted Interaction for Improving Web Accessibility: An Approach Driven and Tested by Userswith Disabilities

148 p.Un porcentaje cada vez mayor de la población mundial depende de la Web para trabajar, socializar, opara informarse entre otras muchas actividades. Los beneficios de la Web son todavía más cruciales paralas personas con discapacidades ya que les permite realizar un sinfín de tareas que en el mundo físico lesestán restringidas debido distintas barreras de accesibilidad. A pesar de sus ventajas, la mayoría depáginas web suelen ignoran las necesidades especiales de las personas con discapacidad, e incluyen undiseño único para todos los usuarios. Existen diversos métodos para combatir este problema, como porejemplo los sistemas de ¿transcoding¿, que transforman automáticamente páginas web inaccesibles enaccesibles. Para mejorar la accesibilidad web a grupos específicos de personas, estos métodos requiereninformación sobre las técnicas de adaptación más adecuadas que deben aplicarse.En esta tesis se han realizado una serie de estudios sobre la idoneidad de diversas técnicas de adaptaciónpara mejorar la navegación web para dos grupos diferentes de personas con discapacidad: personas conmovilidad reducida en miembros superiores y personas con baja visión. Basado en revisionesbibliográficas y estudios observacionales, se han desarrollado diferentes adaptaciones de interfaces web ytécnicas alternativas de interacción, que posteriormente han sido evaluadas a lo largo de varios estudioscon usuarios con necesidades especiales. Mediante análisis cualitativos y cuantitativos del rendimiento yla satisfacción de los participantes, se han evaluado diversas adaptaciones de interfaz y métodosalternativos de interacción. Los resultados han demostrado que las técnicas probadas mejoran el acceso ala Web y que los beneficios varían según la tecnología asistiva usada para acceder al ordenador

Supporting Web usability for vision impaired users

The aim of this work is to provide designers and developers of Web applications with support to obtain systems that are usable for vision-impaired users. To this end, we have defined a number of design criteria to improve Web site navigation through screen readers or other similar devices. A test of navigation by blind and vision-impaired subjects showed that our criteria improved Web site usability both qualitatively and quantitatively. Subsequently, an inspection-based tool was developed to ease application of such criteria. Its main features are presented along with a discussion of some of the first application results

Designing Search User Interfaces for Visually Impaired Searchers: A User-centred Approach

PhDThe Web has been a blessing for visually impaired users as with the help of assistive technologies such as screen readers, they can access previously inaccessible information independently. However, for screen reader users, web-based information seeking can still be challenging as web pages are mainly designed for visual interaction. This affects visually impaired users’ perception of theWeb as an information space as well as their experience of search interfaces. The aim of this thesis is therefore to consider visually impaired users’ information seeking behaviour, abilities and interactions via screen readers in the design of a search interface to support complex information seeking. We first conduct a review of how visually impaired users navigate the Web using screen readers. We highlight the strategies employed, the challenges encountered and the solutions to enhance web navigation through screen readers. We then investigate the information seeking behaviour of visually impaired users on the Web through an observational study and we compare this behaviour to that of sighted users to examine the impact of screen reader interaction on the information seeking process. To engage visually impaired users in the design process, we propose and evaluate a novel participatory approach based on a narrative scenario and a dialogue-led interaction to verify user requirements and to brainstorm design ideas. The development of the search interface is informed by the requirements gathered from the observational study and is supported through the inclusion of visually impaired users in the design process. We implement and evaluate the proposed search interface with novel features to support visually impaired users for complex information seeking. This thesis shows that considerations for information seeking behaviour and users’ abilities and mode of interaction contribute significantly to the design of search user interfaces to ensure that interface components are accessible as well as usable

Usability Tool Support for Model-Based Web Development

When web engineering methods are used for the development of web applications, models are created during the development process which describe the website. Using the information present in these models, it is possible to create usability tool support that is more advanced than current approaches, which do not rely on the presence of models. This dissertation presents ideas for tool support during different phases of the development, such as the implementation phase or the testing phase. For example, if a tool knows from a model that the audience of a website are teenagers, it can examine whether the words and sentences used on the website are likely to be understood by teenagers. An approach is presented to augment existing web engineering models with the additional information ("age" in this case) and to make it available to tools, e.g. via embedding it in HTML code. Two prototypes demonstrate the concepts for integrating usability tool support into web engineering

Understanding and Supporting Cross-modal Collaborative Information Seeking

Most previous studies of users with visual impairments (VI) access to the web have focused solely on single user human-web interaction. This thesis explores the under investigated area of cross-modal collaborative information seeking (CCIS), that is the challenges and opportunities that exist in supporting visually impaired users to take an effective part in collaborative web search tasks with sighted peers. The thesis examines the overall question of what happens currently when people perform CCIS, and how might the CCIS process be improved? To motivate the work, we conducted a survey, the results of which showed that a significant amount of CCIS activity goes on. An exploratory study was conducted to investigate the challenges faced and behaviour patterns that occur when people perform CCIS. We observed 14 pairs of VI and sighted users in both co-located and distributed settings. In this study participants used their tools of choice, that is the web browser, note taker and preferred communications system. The study examines how concepts from the “mainstream” collaborative Information Seeking (CIS) literature, play out in the context of cross-modality. Based on the findings of this study, we produced design recommendations for features that can better support cross-modal collaborative search. Following this, we surveyed mainstream CIS systems and selected the most accessible software package that satisfied the design recommendations from the initial study. Due to the fact that the software was not built with accessibility in mind, we developed JAWS scripts and employed other JAWS features to improve its accessibility and VI user experience. We then performed a second study, using the same participants undertaking search tasks of a similar complexity as before, but this time using the CIS system. The aim of this study was to explore the impact on the CCIS process when introducing a mainstream CIS system, enhanced for accessibility. In this study we looked into CCIS from two perspectives: the collaboration and the individual interaction with the interface. The findings from this study provide an understanding of the process of CCIS when using a system that supports it. These findings assisted us in formulating a set of guidelines toward supporting collaborative search in a cross-modal context