This section describes some of the things you can do to enhance the accessibility of your website. This is not an exhaustive list of web accessibility guidelines; it illustrates some of the techniques that may be used to make your website more usable by a wider population. Wherever possible, the impact for different user profiles is explained.
Text
Keep the content simple
Avoid the use of jargon and complex words. This can be helpful users with cognitive impairments, and benefits all users.
Don’t use justified text
Text shouldn’t be fully-justified as users with dyslexia find this more difficult to read than if the text is left-aligned. They may also miss words which have been highlighted by bold, italics or underline.
Use a non-serif font
A non-serif (also known as sans-serif) font like Arial or Helvetica should be used. Non-serif fonts are easier to read on screen.
Limit the use of graphical text
The use of images of text (often used for important items such as headings or navigation) is undesirable for a number of reasons.
Users who have low vision may prefer different fonts or colour combinations, may need to increase the text using browser options, or use magnification software to enlarge the text beyond the maximum size the browser can offer.
Images of text cannot have their appearance altered by the user – they cannot be enlarged in most browsers, cannot have their colours altered to a higher contrast combination (e.g. white on black) and cannot have their font changed to one preferred by the user.
Unlike normal text, images of text become pixelated when enlarged by magnification software (particularly at higher levels), so users reliant upon this method of access can have significant difficulty in reading the information.
Ensure that font size can be increased
Ensure that text sizes are not fixed and can be resized in the. It is important that text is not a fixed size as some users need a larger print version to make the page more legible. This will enable users who have fine motor control difficulties to increase the font size enabling them to click more accurately on links.
Links and Navigation
Make a big clickable area
Ensure that links and images are a decent size and not too close together. For example ensure that the graphical buttons such as the ‘Go’ button on a ‘Search Form’ is a good size enabling users who have poor motor control to be able to select the button more easily. Separate adjacent links by several pixels – not just one or two.
Use descriptive links
Link text should give the user a clear idea of the destination and make sense when read out of context. Avoid the use of ‘click here’, for example. This is important for screen reader users.
Provide a site map
A site map will allow users to gain an overall feel for the layout, whilst also allowing direct access to any page on the website. If possible, include images or icons to visually sign post the different areas.
Provide skip links
Provide a means to skip over navigation via a ‘skip navigation’ link and on long pages a ‘Back to Top’ link between sections. This enhances the accessibility for users accessing the website via the keyboard as they will be able to select one link to jump over the navigation into the main page content instead of laboriously tabbing through each link.
Ensure that all functionality is available through the keyboard as well as the mouse
This can be checked by tabbing through links and forms using the keyboard to ensure they can be accessed – and in a sensible order. This is important because users with vision impairments will not have good hand-eye co-ordination and are more likely to interact with the website solely through the use of their keyboard. See also Guideline 9 of the Web Content Accessibility Guidelines
Images
Use images and icons
Images and other media used to enhance textual content can often aid in the understanding of the information. This can be helpful users with cognitive impairments.
Provide alternative (alt) text
Ensure that all images have meaningful alt text. This alt text is read out by the screen reader so that the user understands what is being shown on the screen. This is important for users with severe vision impairments. Some people think that they can insert blank alternative text tags for images that are only used for decoration. This is wrong as the screen reader doesn't know if you mean the image to be ignored or just forgot to include some text. If possible decorative images should be set as background images in teh style sheet as these will definately be ignored by the screen reader
Colour
Allow for flexibility
Some dyslexic users find it more comfortable to read text on a beige background. Ensure that colours can be changed in the browser and that they have not been forced by the web developer. If your website has been built using CSS for the layout and colours, you could also consider offering a different stylesheet.
Do not rely on colour alone to convey information
Blind users may not be able to get information about colour definitions from their screen reading software and using colour also presents difficulties for colour blind users.
Use good contrasting colours
Colour contrast can be measured. Juicy Studio’s colour contrast analyser can analyse colour combinations and let you know if they produce enough of a contrast against the W3C recommendations.
Layout
Provide a consistent design
This can be achieved through the use of Cascading Style Sheets where the web developer can reuse the same layout and design for each page in the website. This can be helpful users with cognitive impairments, and benefits all users.
Make use of white space
Good white space separating page elements makes it easier for users with cognitive difficulties to read web pages.
Forms & Tables
Associate text labels with form fields
Associating labels with form fields is important for screen reader users so that they can identify which label describes each form field
Tables
Associate data cells with their headers for data tables
Using table headers for data tables helps a screen reader user to associate the content of a data cell with the row or column it’s in.
Multimedia
Ensure animation can be paused or switched off
Animation can be a distraction and seriously compromise the ability of people with learning disabilities to read content on a page. If you provide moving content ensure there is a way to disable the movement. Alternatively allow it to loop for a few seconds and then stop automatically. See also Guideline 7 of the Web Content Accessibility Guidelines 1.0
Provide captions or transcripts of important audio content
Audio content can be inaccessible to deaf and hard of hearing users. Providing a text equivalent is important for these users but also beneficial to others for example, users in a noisy environment.
Provide text equivalents for a movie
Text equivalents should be provided for an entire movie in cases where the movie can be conveyed using a single text equivalent. Examples include movies that show a simple animation banner adverts or complex multi-media that cannot otherwise be made accessible.
For Flash movies, the text equivalent should be placed in the name field. It is generally advisable to make the contents of this field short and focused in order to describe the function of the movie. The description field can be used for longer descriptions. Some screen readers will read this content by default. Be cautious as long descriptions used can result in an application that is tedious to listen to.
In cases where a single text equivalent is used for an entire movie clip, the ‘child’ objects of the movie should be made inaccessible. This will prevent animations within the movie from causing frequent updates to the screen reader. It also assists automated testing of the content for accessibility.
The text equivalent may be assigned using the accessibility panel.
More detailed information on creating accessible Flash movies at the Adobe Accessibility Resource Centre
Document accessibility
The presentation of lengthy printed documents on the Web should generally be avoided in favour of web pages. However, there are instances where documents will need to remain in their original form e.g. when forms need to be printed and signed. For these documents, there are a basic set of guidelines which should be adhered to:
- Ensure the text is sans serif (e.g. Arial), with a minimum font size of 12.
- Ensure the text is left aligned, not justified as justified text leads to ‘rivers of white text’ being distracting to the reader.
- White space can be just as useful as the text. Over cluttering and complicating the page reduces readability.
- Avoid excessive use of capitalised, underlined or italicised text, consider bold for emphasis.
- Hyperlinks should be spelt out (e.g. in a footnote or endnote) because users may only have access to the printed version.
Styles and Headings
One of the most important things to consider when creating a document is the appropriate use of styles and headings. The inbuilt structuring system of your word processing package should be used when creating any document.
Headings and sub-headings provide an intrinsic structure to the document. An appropriate style should be applied to headings and sub-headings so that the structure is also reflected visually.
Print Stylesheets
Where the use of documents can be avoided, websites should use stylesheets to optimise web page content for printing. These stylesheets should follow the basic guidelines for printed documents.
Microsoft Word
As Microsoft Word is the most commonly used word processing package, it is important to ensure that consideration is given to accessibility and usability within a Microsoft Word document. If a document has been created using the styles and headings options, those reading the document (and also those creating them) can use an inbuilt navigation system (View > Document Map) enabling users to navigate a long document. Clicking the Document Map will allow the user to expand and contract headings or jump to the relevant section of a large document.
PDF (Portable Document Format)
The portable document format (PDF) can be accessible if authors follow established best practices to include appropriate structure and equivalents for users with disabilities. It is important for PDF authors to incorporate within their PDF authoring workflows those steps that result in the creation of accessible PDF files.
PDF is a destination format, that is to say PDF files begin in other applications, such as desktop publishing and word processing programs or as another file type, typically as a TIFF file in the case of scanned content. Measures should be taken to maximise the accessibility in the source in order to enhance the accessibility of the resulting PDF file. The basic guidelines for printed documents should always be followed.
In addition to the basic guidelines for printed documents publishers of PDF files should:
- Favour tools and techniques that will result in the production of accessible PDF documents.
- Use the facilities (if available) in the word processing or authoring application to add alternative text to any graphics that appear in the document.
- Use styles for identifying document elements such as Titles and Headings. Avoid using character formatting techniques such as bolding text and modifying the font and size of text to create the appearance of these structural elements.
- For tabular information, use the product’s table editor (if available).
- If possible, select products that provide authors with the option to export tagged accessible PDF. This will reduce the amount of time verifying structure after the PDF is produced.
- If you intend to create a PDF by scanning a paper document, submit the content to Optical Character Recognition (OCR) and add the necessary accessibility components prior to distributing the PDF file (see section on PDF accessibility repair below).
You Must Improve the Accessibility of an Existing PDF File
If a PDF file is created without following the above guidelines, it may require additional enhancements to improve its accessibility.
For more detailed information refer to the Adobe information for PDF and Acrobat Accessibility
Presentations
Slide Content
When creating presentations a number of slide content issues should be considered:
- Use short concise ideas and content, using bullet points and lists where appropriate.
- When using bullet points and lists ensure every point is ended with punctuation (e.g. a Full Stop, Semi-Colon or Comma). Ensuring this will enable a screen reader user to distinguish between different ideas. Without the presence of punctuation different ideas will be read as a single sentence, without pausing between concepts.
- Write no more on a slide than you would on a postcard. Ensure the text is a minimum size of 24 where possible.
Microsoft PowerPoint
One of the most important features which should be utilised when creating a Microsoft Powerpoint presentation is the Notes Field. It provides presenters with an ideal opportunity to clarify content presented on the slides. It is also important that the Notes Field is used to exemplify the meaning of any visual content. For example if a presentation contains an image of a graph, the Notes Field should be used to explain the content of the graph and its reason for insertion. This will enable a screen reader user to understand the use of any images within the presentation.