Ensure materials are simple, clear and well structured
Wherever possible use common well known words, short sentences, punctuation and if necessary include a glossary. Remember that people do not read online material in the same way as they would read a book, they quickly scan for information of interest - see 'How We Really Use the Web', Chapter 2 of Steve Krug's "Don't Make Me Think" . The WebAxe Podcast and blog provides a number of good Resources for Writing for Web Accessibility. Snigdha, writing for 'Web and Design', provides some good tips in 20 ways to improve Web site readability, everything written here is applicable to text used as eLearning content. 4 Syllables' accessibility for web writers articles gives useful advice on the use of language in web based materials. If text is broken down into chunks these can form ‘landmarks' for some readers with Dyslexia . For similar reasons, ensure individual pages are not too long.
One of the most effective ways to check for clear concise writing is to have your text read back to you, either by a colleague, friends or family or by assistive technology such as the JAWS free download screen reader or NVDA which is one of the best open source screen readers currently available for Windows operating systems. If you use Micosoft Office 2010 you can enable voice to read documents - see the University of Aberdeen Assistive Technology blog entry Proof Reading with free-text-to-speech in Word. Mac/i-phone/i-pad users can have VoiceOver in their operating system read any text documents aloud to them. Such technology also acts as highly effective spell checkers - misspelled words sound awful!
Unfortunately there is no simple answer to the question ‘what is the best font to use for the web?' WebAim's Fonts article provides a good introduction to the practical use of fonts and their effect on readability. The article states that it is difficult to say which font family is best suited for the web and that although ‘conventional wisdom has been that sans-serif fonts are more suited to electronic formats' that 'this convention probably has its roots in the fact that older computer screens were less capable of rendering serif fonts' and that 'most modern computer monitors are capable of displaying all types of fonts with almost as much perceived clarity as a printed page'. Fonts, such as Verdana, Tahoma, Trebuchet MS, and Georgia, were developed specifically for use in electronic media, and are now quite common on both Windows and Mac platforms.
Use margins - It is almost impossible to read text that spans 100% of the page width without getting lost - compare this page for readability with no margins, to the same text with margins on either side.
- Use left aligned text - For many users with Dyslexia justified text with its uneven spacing between words can cause 'rivers' of white space to run down the page, making reading almost impossible.
Avoid blocks of italics and underlined text - On screen blocks of italicised text and underlined text are difficult to read, especially for people with some forms of Dyslexia and certain visual impairments.
Avoid placing text on patterned backgrounds, and if using coloured backgrounds consider using WebAim’s Color Contrast Checker to ensure that sufficient contrast exists between the text and the background. Lighthouse International's colour contrast page gives good practical advice on the use of colour and contrast.
- WebAim make a series of good common sense recommendations for making content accesssible to people with cognative diabilities
When designing documents do not rely upon colour alone to convey meaning as this will create major problems for some people with various forms of colour blindness who have great difficulty distinguishing between certain colours.
Using Styles in Word can make a huge improvement to the accessibility of Word documents. Using Styles gives a document structure. Only sighted users can see that text in bold or in a different colour is meant to be a heading. When Styles have been used a screen reader will announce, and list, headings in a hierarchy enabling users to visualise the structure of a document and navigate to points of interest. Styles can also help with the automated creation of a table of contents for longer documents. Further information can be found at http://webaim.org/techniques/word/. Styles information also transfers across to PDF documents.
In addition to the more obvious using appropriate font sizes, colours and sensible slide transitions the most important things for accessibility in PowerPoint are Styles (and Alt tags). Using any of the in-built templates will ensure Styles are used appropriately. For more detailed advice see: http://webaim.org/techniques/powerpoint/. For advice on using PowerPoint effectively see http://www.jisctechdis.ac.uk/AccessibilityEssentials/2007/AE3/index.html.