Week 10, Digital 21: Web Accessibility

This web site about the Digital 21 Strategy is under of HKSAR government. Digital 21 Strategy strived to position Hong Kong as a leading e-business community and digital city in the globally connected world. The following is the tips for making the web pages more accessible.

1. Provide text equivalent for audio and visual contents
Pure graphical contents are not accessible to users who are vision impaired. Pure auditory contents are not accessible to users who cannot hear. Alternatives should be provided

2. Ensure that the contents can be easily accessed even without using color
Users with color deficiency may not be able to differentiate the different colors and may miss out information that is presented in color alone. A good color contrast will help them to read the information clearly.

3. Identify clearly changes in languages used and make contents simple and convenience to read
Screen reader software with voice synthesizer is one of the assertive tools used by vision impaired users. Some voice synthesizers can 'speak' in multiple languages but changes in languages should be identified for the synthesizers to switch between languages.

4. Modify the structure tables so that they can be read easily and for complex tables, using suitable markup or a linear representation would greatly increase the accessibility
Some assertive tools can render simple tables automatically. Some assertive tools can render simple tables automatically, e.g. by telling the user the format of the table and then read out the contents of the cells one by one. The user can base on the format to map the subsequent contents of the table when the assertive tool is reading the contents. This works well with simple table such as those with 1 heading per column and the contents are similar for all rows, e.g. there are no intermediate totals among the rows.
For complex tables, e.g. those with several logical levels of heading and complex formats, interim subtotals and non-uniform row / column formats and with a large amount of information disseminated, suitable markup or a linear representation of the table will make the information much more accessible.

5. Avoid the use of flickering and blinking contents
Some people, e.g. people with photosensitive epilepsy may have seizures triggered when they encounter fast flickering or blinking objects. Some users, e.g. old people, may not be able to read fast moving information or have difficulties in manipulating fast moving objects.

6. Avoid the use of pop up windows or other windows without telling the user
Although some assertive tools can already switch to the latest opened window and read the contents of the pop up page, pop up windows may cause the following confusions

7. Avoid the use of complicated frames
Frames often make the navigation difficult for vision-impaired users, as the changes in the frame contents cannot be easily detected.

8. Provide clear and consistent navigation mechanism
Always make your site easy to navigate so that the visitor can move around the site easily and find the information / services required quickly.

Summary
Improve accessibility can gives an opportunity for disabled person to obtain the service and information from the Internet. It can increase the general usability of a website. In the business view, accessibly websites can serve more people include the disability and other customers in general