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different preferences to view and control the document from those in the published version. The success criteria are as follows:

1.The author must be able to configure the presentation settings of editing views without affecting the web content being edited.

A.1.5. Ensure that information, functionality and structure can be separated from presentation (Priority 1). Separating content and structure from presentation allows different authors to use different interfaces and authoring tools without losing any information or structure. The success criteria (which are being revised) are currently as follows:

1.Information conveyed by variation in the presentation of text, e.g. by spatial location, must also be conveyed in text or made available programmatically.

2.Information conveyed by colour must also be conveyed in text or made available programmatically and conveyed in a way that is visually evident when colour is not available, for instance by shape.

3.If content is structured the structure must be made available programmatically.

4.If the sequence of content affects its meaning, the sequencing information must be made available programmatically.

12.7.3Accessible Adobe Portable Document Format (PDF) Documents

Adobe PDF documents are frequently used on the Web and to distribute electronic documents over corporate networks, by email and digital media. Therefore, it is important that PDF documents are fully accessible. Adobe has produced a document on using the most recent version of its software, Adobe® Acrobat® 7.0, to create accessible PDF documents (ADOBE, 2005a), as well as information on the accessibility features of versions 6.0 and 7.0. This includes a list of features for accessible PDF documents, which could be taken as accessibility guidelines. However, there does not seem to be any information on PDF accessibility produced independently of the manufacturer or any surveys of blind and visually impaired people to investigate their experiences with PDF documents other than the small-scale survey performed by the authors (Hersh and Johnson 2006). In addition, a number of accessibility features are only available in the Professional version, whereas many users only have Adobe® Reader® or Acrobat Standard. This then puts a practical limitation on the likelihood of PDF documents being fully accessible.

Accessible PDF documents have the following characteristics (ADOBE, 2005b):

1.The document is a searchable text file rather than an image-only scan. Therefore scanned document files require the application of optical character recognition to make the image produced by scanning into searchable text with selectable graphics. Both Acrobat 7.0 Professional and Standard are able to convert scanned images to searchable PDF documents.

2.Any form fields should be accessible. If the PDF document is a form to be completed, then the interactive (fillable) form fields and their descriptions

need to be readable by screen readers and there should be a preset tab order to facilitate navigation among the form fields. Acrobat 7.0 Professional and LiveCycle® Designer have these features.

3.The document structure is indicated by tags. Accessible Adobe PDF documents use tags to indicate structural elements of a document, such as titles, headings, figures, text and tables, and the relationship between these elements. Although different assistive technologies may process document structures differently, using a consistent tagging system generally improves accessibility for disabled people. Some documents can be prepared for tagging before conversion to PDF or tags can be added to documents in PDF form.

4.The reading order should be clear and easy to follow. Assistive technology is designed to read page content in the order the content is received from an application. Therefore if the order is not logical, for instance if a heading is after its text or a figure caption is separated from the figure description, disabled people may not be able to make sense of the content. A structured reading order is generally produced by tagging. However, the reading order may need to be corrected in complex documents and this generally requires Acrobat 7.0 Professional.

5.A descriptive text is provided for all graphics, links and form fields. Accessible Adobe PDF documents have descriptive or alternate text to describe illustrations, graphs, charts form fields and links, as screen readers are not able to read graphical elements. The alternate text enables screen readers to interpret them and read a description to the user. Descriptive text about screenreaders and URLs, which can be read by screen readers, facilitates navigation. Acrobat 7.0 Professional is required to add alternate text and descriptions to PDF pages.

6.Navigational aids should be provided. Accessible PDF documents provide navigational aids in the form of links, bookmarks, useful and frequent headings, a detailed table of contents and an optimised, preset tab order for forms and embedded links. Users can use these navigational aids to go directly to a particular place in the document without having to read the whole document. Most navigational aids can be set during conversion from authoring applications to PDF. Bookmarks and links can be set using Acrobat 7.0 Professional or Standard.

7.The document language is specified to enable multilingual screenreaders to switch between languages during operation. Both Acrobat 7.0 Professional and Standard can set the document language for the whole document, whereas the Professional version is required to set different languages for different parts of a multi-language PDF document.

8.The fonts used allow characters to be extracted to text. This requires fonts to contain sufficient information to enable Adobe Reader or Acrobat to extract correctly all the characters to text. For instance, characters are extracted to text when users listen to the text using a screen reader or the Read Out Loud tool in Adobe Reader or Acrobat or when they copy, paste or save text to a file. If there is insufficient font information, incorrect output may be received, with

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words or characters omitted or question or other marks added when a PDF file is copied, pasted or saved as text. Some fonts are inaccessible in the sense that they do not contain sufficient information for Adobe Reader or Acrobat to correctly extract all the text characters. These documents can be read on the screen, but cannot be read by screen readers and therefore such fonts should be avoided. Only Acrobat 7.0 Professional is able to check for the presence of inaccessible fonts.

9.The security settings should not interfere with screen readers. Settings to restrict copying of part of a PDF documents could interfere with screen readers, since they carry out a type of copying in order to read the text back. Acrobat 7.0 Professional and Standard both have an option which resolves this problem, called ‘Enable text access for screen reader devices for the visually impaired’.

Acrobat 6.0 and 7.0 and the free Adobe Reader also have a number of accessibility features including the following (ADOBE 2005a,b):

•Synthesis of the text into speech so it can be read aloud to enable the reading order to be checked. Although a screenreader is not required, it is advisable particularly for complicated texts, as it provides better navigation, allows users to toggle between table and text reading modes and allows access to PDF forms as well as documents. Acrobat 6.0 uses Microsoft Active Accessibility, an application programming interface which provides information about the content and user interface of Windows-based programs to assistive technologies using speech and/or refreshable Braille displays. Since Microsoft Active Accessibility is widely supported, Acrobat 6.0 can be used with a number of different screen readers and other assistive technologies.

•Evaluation of the accessibility of a PDF file so that blind and visually impaired people know whether it is accessible and can be read in the correct order. This is done using the Reader Quick Check Feature which can indicate whether the document is a scanned image or tags are present.

•Customising the font size in the navigation panels. Increasing the font size of the navigation panels can enable visually impaired people to read bookmarks, comments and signatures in a PDF file.

•Choosing alternate reading orders. Improving the reading order of text and form fields can be important to users of screen readers in documents that have not been optimised for accessibility. There are three options:

•The default is allowing Acrobat to determine the reading order using columns, boundaries, form fields and other layout information in the PDF file.

•Acrobat uses the word order in the PDF document’s print instructions.

•Acrobat reads the page from left to right and top to bottom.

•The ability to view documents in high contrast mode to improve readability. Colour contrast can be increased in Acrobat 6.0 by replacing the specified colours in the document with custom colour schemes created by the user or high contrast colour settings defined in the operating system.

•Zooming in on the text and reflowing it to fit any size view. Viewing tagged PDF files using the Acrobat 6.0 reflow feature allows users to use large type display and the text to automatically reflow to fit the available screen space. This is preferable to magnification and manual scrolling.

•Saving PDF content as text to use with a screen reader that is not compatible with Microsoft Active Accessibility, enabling the opening of files containing tables or other content that is too complicated for the Read Aloud function and sending text to a Braille printer.

•Tagging of existing PDF documents using Acrobat 6.0 to enable better performance with a screenreader.

Some features require the use of Acrobat Professional 6.0 or 7.0. These include identifying accessibility problems and automatically inserting each form field into the tag to allow the recognition of form fields, identification of proper reading order and reading any descriptive text.

12.7.4 Bobby Approval

The Center for Applied Special Technology (CAST) was set up in 1984 to develop innovative technology-based educational resources and strategies based on ‘Universal Design for Learning’, which requires the following:

•Multiple means of representation, to give learners various ways of acquiring information and knowledge.

•Multiple means of expression, to provide learners with alternative ways of demonstrating what they know.

•Multiple means of engagement, to take account of learners’ interests, offer appropriate challenges, and increase motivation.

In 1996, CAST created a webpage evaluation tool called Bobby to encourage webpage designers to adhere to the W3C accessibility guidelines. The concept is that the Web should be a resource for all to use. A free version, called WebXACT, is available (WebXACT, undated), but can only be used to test single pages of web content for quality, accessibility and privacy issues by entering the URL of the page. Testing a website consisting of several pages would require the URL of each page to be entered separately. The full version was commercialised when Watchfire acquired Bobby from CAST in 2002 and took over the responsibility for development, marketing and distribution of the technology. The current version can be purchased as Watchfire Bobby 5.0 (WB, undated). It is intended to be a comprehensive web accessibility tool and encourage compliance with both the W3C Web Content Accessibility Guidelines and Section 508 of the US Rehabilitation Act.

Bobby spiders through a website and tests each page for compliance with accessibility requirements, including readability by screen readers, the provision of text equivalents for all images, animated elements, audio and video displays. Bobby can see local webpages, as well as webpages behind firewalls. It performs over 90 accessibility checks. During a scan, Bobby checks HTML file against selected