Fig. 1 Original vs. Low Vision adapted web site
This extend abstract is a contribution to the Text Customization for Readability Symposium. The contents of this paper was not developed by the W3C Web Accessibility Initiative (WAI) and does not necessarily represent the consensus view of its membership.
Many existing web sites are designed such that there are access limitations for some user categories, like users with low vision or users with dyslexia. Some of these limitations are related to text size, colors and style. The limitations presented can be over passed by using tools that can adapt the style of the original web site. However, some of these tools can be troubled by some styling design considerations.
In order to customize text on existing web sites users can adjust their operating system settings or browser settings. When these are not available or more advanced customization is needed user can chose among specialized client side tools or browser extensions (see Chrome High Contrast website (2012)). However, in some cases the user does not has rights or possibility to change the settings on the client side nor to install applications. For such cases the best options are server side solutions that need no installation and are device and browser independent. One category of server side solutions are the transcoding services. Example of transcoding tools are: "Access Proxy", a tool designed by Brown and Robinson (2001) for low vision users; BETSIE tool developed by Myers (1998) from BBC; Web Accessibility Service developed by Hanson and Richards (2003) from IBM; WebAnywhere, online text magnifier and screen reader developed by Bigham, Prince and Ladner (2008).
This paper presents text4all, a server side transcoding solution designed to enable style customization and language adaptation on target websites. The style customization part will be discussed briefly in this paper. In order to perform the style customization, the tool is overriding the original style of a given web site with a custom one. Several style templates were chosen for specific user categories. A style for low vision users (the style was created by the first author of [2]). Compared to other existing solutions text4all brings several new possibilities: it offers language adaptation and translation services, that can be combined with text customization in order to increase accessibility; compared to [BETSIE] it does not limit the input websites to certain domains; text4all also has some limitations like problems with web sites that use client side scripting for DOM manipulation, complex/dynamic websites or web sites that need authentication. A person with low vision was involved in the design and test phases. A style for users with dyslexia is under development (based on the guidelines provided by Rello, Kanvinde and Baeza-Yates (2012)).In the current phase, the user can only override the default style with one of the given templates. The default templates were chosen based on existing user studies (like the one performed by Rello, Kanvinde and Baeza-Yates (2012)). Usage of predefined templates can be useful especially when rapid adaptation is needed, so the user doesn't need to customize multiple settings. However, we realize the importance of detailed customization, and this part is under construction. The customization will address options like: text size, text color, background color, font, character, line and paragraph spacing, column width; Figure 1 presents a screen capture example of low vision adaptation performed by text4all. .
Fig. 1 Original vs. Low Vision adapted web site
Fixed positioning
One of the technical challenges in relation to text customization was the Fixed and Absolute CSS positioning. Since one of the most important customization needed in order to increase the accessibility on a web site is text size, the positioning used for the text can be an issue. Bigger text needs more space. When Fixed or Absolute CSS positioning is used, the increased text, in order to be positioned to the given position can be overlapped, making it impossible to read (see figure 2). The workaround found for this situation was to override the CSS positioning.
Fig. 2 web page with fixed
positioning: Original vs Adapted
Original vs. reorganized layout
Changing the size of the text, character/line spacing and column width may affect the original page layout. If the original layout is preserved, usability issues may occur (like the need for horizontal scrolling). On the other hand, reorganizing the page into a single column layout for example may confuse users that were used to the original layout, or may produce other usability issues, like menus being moved and hard to locate. Probably the best solution is to let the user decide from the two options.
The tool developed can be found at http://www.text4all.net. It is still work in progress, but is functional. It works in any browser and any operating system. It may be the ideal solution for navigating on internet from places like public libraries, internet cafes or any other location where installing special software is impossible or hard to do. text4all home page takes as main input a target web page and a set of operations to be applied on the target site, most important for low vision users being "high contrast" operation. Additionally to the high contrast operation, the user can choose to apply some language processing operations on the target web site in order to cope with language specific limitations. One of the open questions left from this research, in relation to text size adaptation, was it is preferable to try to preserve as much as possible the original layout versus reorganizing the layout.
The open question on preserving the original layout versus reorganizing the layout should be evaluated upon users. The evaluation should be done on each user category, since the result of adaptation may vary significantly.
Related to the original vs. reorganized layout, investigate if there are other options (outside letting the user or the system choose among them).
The next steps in text4all project for the near future are:
- finishing the support for detailed customization;
- finishing the templates for dyslectic persons
- performing user studies with people with low vision and dyslexia