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Tag: tools

Accessible Web Search for the Visually Impaired

Google cleaned up their search experience with their accessible search engine. Fairly similar to the regular search, but with some subtle differences that can aid a visually impaired person to search better.  The system is still being developed but basically it prioritizes results that are accessible.

Check it out a: Accessible Web Search at Google

To learn more: Making Search Accessible to Visually Impaired Users and Is your Web Site Optimized for Accessible Search?

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Check My Colours

www.checkmycolours.com is a website for you to easily check if the colours on your website are accessible.

This tool takes all of the references to colour from your web page including your CSS and nicely compares the background colours to the foreground colours. The report that gets tabulated shows very bluntly what instance is acceptable and what instance is not. The system analyses three things: Contrast Ratio, Brightness difference, and Color difference. By clicking on the rows, it also allows the user to find another colour that would replace the current one. Unfortunately, this feature is a little hard to click on.

The site can give the user an idea of what is lacking in terms of colour accessibility, but does not offer a comprehensive understanding of what the guidelines are. Explaining what the categories and the numbers mean might clarify the systems results.

Let me demystify it for you.

Contrast Ratio: Contrast is measured using a formula that gives a ratio ranging from 1:1 (no contrast) to 21:1 (maximum contrast). AA and AAA refers to the level of priority. Level AA are strongly recommended (mininum contrast is 4.5:1) to allow most users accessibility. Level AAA are suggested (mininum contrast is 7:1) to allow some users accessibility.

Algorithm for luminosity contrast ratio in Web Content Accessibility Guidelines 2.0 Glossary.

Brightness difference: Another formula that evaluates the difference between the background brightness, and the foreground brightness. This should be greater than 125.

Color difference: This formula refers to the difference between the background colour and the foreground colour  and should be greater than 500.

Formulas are explained in the document Techniques For Accessibility Evaluation And Repair Tools.

The limitation of these types of applications is that we cannot check the colour balance from images.  This is one of the reasons that it is not recommended to make any text into images. They cannot be viewed by external reading programs.

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Reviewing an authoring tool

I was going to do an evaluation of an authoring tool, but the WAI have thought of it already at www.w3.org/WAI/AU/2002/tools.

I found that the reviews were all a little outdated and I didn’t get a definite conclusion from any review. So I finally decided to go ahead and check out an authoring tool myself. I went for the markup editor developed in collaboration with the W3C, Amaya. It’s a WYSIWYG editor/browser. Many distributions are available. I will be looking at the Windows one.

I opened an existing file that I know is made to standard and it came out all distorted. I then created a page from scratch. I must admit that I’m not used to any kind of authoring tool. I have been using Notepad++ for a while. So it was a little strange. At first it took me some time to get used to the application itself, but after a while of playing with it, it was fairly simple to use. I did a trivial page with a menu, an unordered list, a form and an image.
Page done with Amaya

Page done with authoring tool Amaya
Page done with authoring tool Amaya

Formatting done to some text resulted in inlining style, there were extra open and close paragraphs, inserting the image required to enter an alternative text, and as for the other elements they were pretty intuitive.

It’s clear that you still need to know some basic concepts in web standards to make any web page complaint or accessible. This tool might be good for someone just starting, but I think I’ll just stay with my simple text editor.

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Evaluating a website for accessibility

The W3C has extensive information on how to properly evaluation a sites accessibility. Here are the underlining steps to ensure that your evaluation is full-proof:

For a preliminary review, select a page that is representative of the whole site or that most people will see. Try to choose a page that has tabular data, images and scripts. And then:

  • Examine this page for alternative text,
  • Divs instead of tables for page layout,
  • Use the keyboard instead of the mouse for navigation,
  • Test with different font-sizes and screen resolutions.

The Firebug and Web Developer extensions in Firefox will make your life easier in accessing the code and disabling images and even resizing your browser size. It might be a good idea to try a screen reader, and not to mention an Web accessibility evaluation tool like AChecker. These will enhance your understanding of the sites limitations and successes.

Another important part of evaluating a site is to get people with disabilities involved in the process. Some may have insights that other users will not.

For a complete procedure of website evaluation you have to go to the W3C – Web Accessibility Initiative page.

Although a little outdated, the WAI also provides a comprehensive checklist of accessibility guidelines (WCAG 1.0) and an useful template for the final accessibility report. They really thought of everything!

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Firefox Accessibility Extension

Firefox 2 and Firefox 3 let the user add plugins to the browser. There are about a million of them that you can find either on the menubar under Tools and Add-ons or at their website at addons.mozilla.org. The add-ons that any web developer must have are Firebug, to debug the code and make adjustments on the fly; Web Developer, to disable, highlight, display, outline, and validate just about anything on any web page; and a recent discovery of mine Firefox Accessibility Extension.

Although Firefox Accessibility Extension has similar features than the Web Developer add-on, it’s still pretty sweet. Not only does it give the user a toolbar, but also an extra heading on the menubar, between Tools and Help, which I personally prefer rather than having a bunch of toolbars taking up space on my browser. The greatest feature of this extension for a web developer is that you can validate your web page for accessibility. Its FAE Rule Set is based on Functional Accessibility Evaluator 1.0.1 developed by the University of Illinois at Urbana-Champaign.

FAE on the menubar
FAE on the menubar

If you have any mistakes these are listed in a window with a description of  the error. Obviously there’s a learning curve where you have to know the terms that the report is referring to, nothing a little research won’t solve. These rules are very straightforward, but not exhaustive. This tools gives you a simple and fair reading of your page and this is already a very good starting point.

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