Dena Shumila
Jan Richards
INTRODUCTION
Before the invention of computers and computer adaptations, the primary problem with blind access to information was that manual means were required to translate large quantities of printed material into braille or audio form. Screen readers and brailledisplays were then esigned to interpret text files which had been previously created with the average computer user in mind. Optical Character Reocnition (OCR) software then allowed blind computer users to scan printed information into their computers. This data could then be read with a braille display, a screen reader, or screen magnification software. The World Wide Web (WWW), in conjunction with adaptive technology has now offered blind and visually impaired computer users the opportunity to access the Internet: the largest repository of information the World has ever seen. The recent popularization of the Internet has spawned the growth of the World Wide Web: an easy-to-use, point and click document retrival system. The fact that the vast majority of the information on the Internet now occurs in the form of primarily text-based Web documents makes it a valuable resource for all users, particualrly those with disabilities.Each World Wide Web document, refered to as a web page, is scripted in HyperText Markup Language (HTML) code. Like pages in a book, web pages can be complex combinations of printed words and graphical representations. However, these pages, unlike their paper counterparts, contain "active" HyperLinks which, when selected,cause another pre-specified page to be displayed. These hyperlinks can be either text, usually displayed in a different colour and underlined or clickable images. In addition to displaying other web pages, clicking on these "hotspots" may display related graphic, audio, or video information.
The HTML protocol provides a flexible, and relatively easy-to-use technique for producing an array of document styles. It is this freedom in the document creation process that actually limits access to the World Wide Web, for persons with visual disabilities. The following subsections illustrate problems, and suggest possiblesolutions for overcoming the limitations created by inaccessibility.
SOLUTIONS & SUGGESTIONS
Writing HTML code for screen reader users is difficult at first, because it often involves a complete change of perspective on the part of the authors. Sighted people tend to rely heavily on their ability to perceive the computer screen as a whole, and depend primarily on visual feedback to gather important information.1) OUTLINES:
Rather than assuming that users are capable of scanning the Web document, and understanding its structure as a whole, HTML writers should place a general outline at the point on the page where a screen reader would begin to read. This need not change the appearance of a web document since this information can be displayed as Alternate (ALT) Text inside a graphic page header. Similar explanations should be presented at other points in the document, particularly if it is long or divided into distinct subsections.These outlines are valuable to blind users because screen readers only provide information about a document's format one piece at a time. In addition, screen readers do not normally alert blind users to the presence of paragraph indentations, centred titles, bolded and underlined text, columns... In fact, if the screen reader is instructed to read the whole screen, the program will wrap around lines, skip over blank spaces, and ignore text attributes like highlighting and footnotes. It is then necessary to issue specific "find" commands to obtain such information. Outlines can identify relevant features of the document, such as its length, the number of HyperLinks it contains, and a description of its general content.
2) TAGS & LISTS:
Tags can be used in conjunction with outlines to provide information about page breaks and lists. For example: they can appear as ALT Text within graphical page separators. The Adaptive Technology Resource Centre (ATRC)'s own home page uses tags by placing a single dash on either side of the tag's text. However, they can be implemented in various ways.Tags can also be used when labelling and constructing lists. For example: "- List with 7 choices -". Each of the 7 choices should then be numbered, so that readers can remember the numbers of the choices that interest them. The numbers also break up the text, providing a distinct separation between each item. For the sake of contrast, sub-lists could then be represented alphabetically. Avoid using the HTML list elements, because screen readers may interpret these markers as asterixes or ignore them altogether. Horizontal lines should also be avoided, because a screen reader, working in conjunction with certain browsers, could mistake them for text entry lines in a form. Vertical lists may also be misinterpreted by the screen reader. Although they are easy for sighted users to identify, blind readers lack the following vital information, when dealing with the typical list format. When and where does the list start and finish? When and where does each list item start and finish? Are there sub-lists? How many list items are there? The need for this kind of information further supports the value of tagging and describing lists, as well as numbering their items.
3) GRAPHICS:
Graphics present a serious accessibility problem, that has little chance of being completely overcome. The old saying that "a picture is worth a thousand words", sums up the dilemma. Images and other inaccessible elements are commonly used to deliver messages that would take several words to convey. This means that information can be distorted, or even completely absent from the perspective of people with visual disabilities. Therefore, it is up to HTML programmers to provide alternative access options for those elements which can be misinterpreted by screen reader packages, or by the browsers themselves.Text is obviously the most accessible medium, since it is the only type of information that a screen reader will readily interpret. However, many authors of Web sites fail to make the distinction between actual text©based pages, and mere photographs of words. Alpha-numeric characters contained within Bitmaps are not interpreted properly by screen readers.
What is the proper balance between text and images? The ATRC's Web site uses ALT Text for every image. However, this ALT Text often conveys the message of an icon, but says nothing about its design or its relation to the page. This system, although functional, presents a problem for blind readers who value information about visual appearance and spacial position. For these people, a possible solution might be to include a short description of these features in the ALT Text of a page header. This method still falls far short as a substitute for the aesthetic and explanatory role of pictures. An area where ALT Text can prove somewhat ineffective is Image• Maps. Image Maps are pictures that have been specially designed to be clickable. This means that clicking in different areas of the image will take you to different HyperText documents, or other related photographs. The primary problem with image maps is that screen readers cannot recognize them, or the words and/or graphical instructions that they often contain. In addition, the clickable surface must be navigated by a mouse, and selections made on the basis of the image. Totally blind individuals might have considerable difficulty navigating with a mouse. For the present time, a text-only page must be constructed as an alternative to the image intensive one.
4) LINKS:
Many sites, including the ATRC's, utilize clickable buttons to provide the user with a better idea about their destination and a larger target to click on. However, having an active image serve as a button or link is a problem since blind users will simply see the word "IMAGE" as a link to an unknown location. This problem could be solved if images were designed with ALT Text. However, because the ALT Text is contained within the size defined for the image, small buttons may not display their ALT Text properly. Therefore the button should also have an external text label. The text for this label should be contained within square brackets, because many screen reader users have their software configured to identify these words as HyperLinks.When constructing a link to another page, HTML authors often use sentences like "Click here to learn about the moon." Unfortunately, they choose to make the words "Click here" the link, and for people using voice output software this can be extremely confusing and uninformative. This is because screen readers are typically designed to move through Web documents one link at a time. Writers are advised to incorporate meaningful words into their links. In this way, users who skip from link to link can get an idea of the choices available without being confronted by a barrage of meaningless commands.
5) FORMS:
HTML form elements, including input text areas, radio buttons, check boxes, and pull down menus are intended to facilitate interactive communication between clients and servers. Forms allow for automated responses to large quantities of feedback. The fastest elements for sighted people to use are the pull down menus and checkboxes since they can be activated completely with the mouse. However, screen reader users rely much more heavily on text to understand the page and enter their input. Text based browsers make this a difficult job by badly distorting the page to cope with things like pull down menus. A temporary solution might be to use exclusively text-based input, even though this increases the possibility of problems such as spelling errors. The other elements must be redesigned with access in mind. For example: avoid horizontal line breaks because they are read the same way as text entry areas. Also avoid default text entry which can be confused with the preceding instructional information. When constructing forms, it is important for writers to clarify where text entry fields occur, and which information is being requested.6) ADDITIONAL CONSIDERATIONS:
In short, Web pages designed for screen reader users should always be kept simple and concise. Uncommon typographical characters or constructions should be omitted. Also, remember that screen readers read every word, so make an effort to keep things simple. Exclude irrelevant information, such as descriptions of page borders and decorative graphics. Simplicity will make it less time consuming for blind readers to navigate a document. Efficiency is also increased if text only alternatives to more image intensive pages are offered. For blind users, loading images is simply a waste of time, because they do not enhance their exploration of a site.Another important fact to consider, is that not all sight impaired people suffer from a total loss of vision. There are various eye disorders, such as colour blindness, tunnel vision and, an inability to focus. Each of these conditions impedes the processing of visual information in a different way. Therefore, thought should be given to the size and colour of text and images, the level of colour contrast, and the design of the document's background.