Latest Accessibility News on Accessify

Web Accessibility Tools Consortium colour contrast analyser 1.1

The Web Accessibility Tools Consortium and Vision Australia are proud to announce the colour contrast analyser version 1.1.

Packed with new features:

  • Choice of test algorithms (luminosity and colour/brightness)
  • Input hex or RGB values
  • RGB sliders to tweak colours on the fly and get results instantly
  • Simulation functions that allow application of colour blindness and other simulations to screen captures, existing images, and real time simulations via a draggable “simulation window”
  • Button copy results to clipboard for insertion in documents

A huge thanks to Jun for all his work on this project and thanks to Gez Lemon, Sofia Celic and Andrew Arch and pixeldiva for their feedback during development. And a minor pat on the back to my humble self [Ed.: Steve Faulkner from the National Information Library Service]

Filed under: Accessibility
Comments Off Posted by Patrick H. Lauke on Tuesday, April 18, 2006

GrayBit version 1.0 launched

Congratulations to Mike Cherim and Jonathan Fenocchi for the launch of GrayBit 1.0

GrayBit is an online accessibility testing tool designed to visually convert a full-color web page into a grayscale rendition for the purpose of visually testing the page’s perceived contrast.

Regardless of a few very minor bugs, the converter works very nicely, dealing with images referenced in the HTML, as well as any images and colours defined in the CSS. Moreover, all link references in a page are changed to run through the converter as well, so that you can do an entire run through a site and view the converted version of each page…slick.

It’s worth noting, though, that, as useful as this tool is, it still only provides a way to carry out a subjective assessment of a page’s contrast. A human tester running pages through the converter still has to make a personal judgement call on whether or not contrast is sufficient. Also, this tool does not (yet?) simulate the effect of different types of colour blindness (which not only influence the hue, but also the perceived brightness of colours). And lastly, the mathematical conversion to greyscale used by GrayBit may not complete match the subjective brightness perception of the original colours; for instance, compare the top banner on Jona’s page in its original and converted forms - the greyscale version of the gradient appears darker (to me, anyway) than the fluorescent green one, giving the impression of a far better contrast than originally present.

All in all, though, this is an excellent tool to demonstrate the reason why a site shouldn’t rely on colour alone to somebody who may not even be aware of the potential problem encountered by users with colour blindness. Use it in conjunction with Gez Lemon’s colour contrast analyser for slightly more objective results.

Filed under: Accessibility
Comments Off Posted by Patrick H. Lauke on Monday, April 17, 2006

Google Provides Audio CAPTCHA

Via Matt Bailey’s Web Site Accessibility Blog, news that Google is providing an audio alternative to its visual CAPTCHA. These tests - that aim to filter out automated bots (and hence spammers) from real human beings - also have the unfortunate side effect of filtering out blind users. Can’t see the text on screen? Can’t come in then! Inthe audio version "the numbers use a combination of speakers in what sounds like a busy cafe", according to Bailey. I’ve not tried this out for myself yet (as I write this, I am at a machine that does not have the Quicktime plug-in required) but if you feel like trying out for yourself, head on over to Google Groups and try setting up an account.

Filed under: Accessibility
Comments Off Posted by Ian on Thursday, April 13, 2006

Roger Johansson on ALT attributes

It seems like there is a bit of confusion among many web developers and browser vendors surrounding the use of the alt attribute to provide alternative text for images and other non-textual elements.

A nice round-up from Roger Johansson: Alt text is an alternative, not a tooltip.

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Comments Off Posted by Patrick H. Lauke on Tuesday, April 11, 2006

Disability podcast from the Beeb

Actor Mat Fraser and comedian Liz Carr host the first edition of our monthly disability talk show that you can listen to on your computer or download onto your iPod or MP3 player.

For subscription details and full transcripts (in RTF), see the BBC’s Ouch! podcast site.

Filed under: Accessibility
Comments Off Posted by Patrick H. Lauke on Monday, April 10, 2006

Chris Heilmann on why clients don’t care about accessibility

An oldie, but I only just now got around to posting it here: Christian Heilmann’s article for Digital Web Magazine: 10 Reasons Clients Don’t Care About Accessibility.

Stop selling accessibility as a technical issue. Address it in the scoping and design phase rather than at delivery.

Filed under: Accessibility
Comments Off Posted by Patrick H. Lauke on Monday, April 10, 2006

Jodi Awards 2006

The winners of the 2006 Jodi Awards for excellence in museum, gallery, library, archive and heritage website accessibility were announced on Thursday, 6th April, at a ceremony at the British Museum.

Read the full press release at the MLA site.

Filed under: Accessibility
Comments Off Posted by Patrick H. Lauke on Monday, April 10, 2006

Paul Boag podcast on accessibility guidelines

In this weeks show we get “down and dirty” with web accessibility, including a step-by-step tutorial into the WAI guidelines.

Get Paul Boag’s podcast Understanding accessibility guidelines, which gives Paul’s fairly good run-down of WCAG 1.0 checkpoints. Unfortunately there’s no transcript…

A few notes I made while listening to this:

Time Checkpoint Paul’s take Note
14:42 If you go on to the effort of being AA compliant, you might as well be AAA - because it’s not a huge step on. I suppose it’s a bit more fiddly… This depends on how you interpret checkpoint 11.3: provide information so that users may receive documents according to their preferences. and checkpoint 14.2: supplement text with graphic or auditory presentations where they will facilitate comprehension of the page.. If you’re strict about them, AAA can almost never be achieved, only strived towards.
18:10 Checkpoint 2.1: ensure that all information conveyed with color is also available without color. As an example, Paul suggests using bold and red, rather than just red, to denote required fields in a form. This helps only if you’re trying to help a sighted user who is colour blind (or a user on a device that doesn’t support colours). However, a blind users won’t get much from the bold visual styling either. It’s best to make required form fields absolutely explicit by adding an actual bit of text in the field’s label, for instance.
22:30 Checkpoint 6.2: ensure that equivalents for dynamic content are updated when the dynamic content changes. You change the page title for a particular page…now, if you’ve used images for the page title, and you used image replacement…you don’t want the text to be the new title but the image to be the old one. True, but what possibly happens in more cases is the opposite: the image is changed (by a visual designer), but the alternative/replaced text isn’t…as rightly mentioned later on.
23:25 ALT tag A cheap shot, but it’s always worth reminding people: it’s an ALT attribute, not a tag.
24:30 Checkpoint 7.1: until user agents allow users to control flickering, avoid causing the screen to flicker. Hard to interpret, what’s flashing…open to interpretation

There are some general rules of thumb with regards to problematic flickering frequency:

Seizures can be triggered by flickering or flashing in the 4 to 59 flashes per second (Hertz) range with a peak sensitivity at 20 flashes per second as well as quick changes from dark to light (like strobe lights).

The duration and size of the flashing area also plays a part (for this last point, as an extreme example: a single pixel that flashes will not have the same seizure-inducing effect as the entire screen flashing).

28:24 Checkpoint 9.1(provide client-side image maps instead of server-side image maps except where the regions cannot be defined with an available geometric shape. Paul notes that he doesn’t really get this one.

Client side image maps (which are really the ones most commonly used nowadays) can only have simple geometrical areas defined as hotspots (rectangles, circles, polygons). Server-side image maps, on the other hand, can have all sorts of shapes. When the user clicks on the server-side map, the X and Y coordinates of the click are sent to the server; here, you could have all sorts of processing to work out what was clicked…you could define any type of shape, even have a different destination for every single X and Y coordinate pair / pixel.

Now, client-side image maps do not require a roundtrip to the server to work out what url the browser should load. Also, the regions defined in the client-side map can be accessed via the keyboard (tabbing through like normal links in most visual browsers), whereas server-side image maps (where the browser has no clue what, if any, areas of the image are hotspots) simply cannot be actived via the keyboard (unless you use a virtual pointer or similar). Hardly seen in the wild, but something very much related (and just as bad) are image inputs in forms, for instance the world map at geourl.org (if you’re using the X and Y coordinates, and not just taking advantage of the image input as a “stylish” alternative to a proper submit button).

30:45 Checkpoint 12.1: title each frame to facilitate frame identification and navigation. That’s so you can bookmark them and stuff like that… No, the checkpoint is not referring to the title of the document contained in the frame. It refers to the title attribute of the frame in the frameset definition. This way if a user with assistive technology comes across the framed site, they can get information about what each frame contains before they dive into it (e.g. a frame titled “navigation” and another one “content” (see the associated HTML technique for details).
32:00 Checkpoint 1.3: until user agents can automatically read aloud the text equivalent of a visual track, provide an auditory description of the important information of the visual track of a multimedia presentation. This is a slightly controversial one that most sites claiming full AA or AAA don’t do. Admittedly, the effort involved with creating a good audio description is quite high.
38:50 Checkpoint 3.1: when an appropriate markup language exists, use markup rather than images to convey information. You can still be priority 2 compliant and use images for headings as long as you’re doing it with web standards again where you’re using an image replacement technique. Just to clarify that image replacement techniques are not web standards per se. I can still use an IMG element and follow web standards, and in many cases I have argued that this is still acceptable (provided that the contrast and size of the text used in the image is ok enough for most general situations).
39:28 Checkpoint 3.2: create documents that validate to published formal grammars. As already pointed out in the podcast comments, this has nothing to do with cognitive disabilities and bad grammar being hard to read. It’s about your markup validating (passing W3C HTML/CSS validators). It was fun to listen to the very elaborate rationale, though.
43:05 Checkpoint 3.3: use style sheets to control layout and presentation. You cannot be priority 2 compliant if you’re doing table based design. As noted later, unfortunately checkpoint 5.3: do not use tables for layout unless the table makes sense when linearized. is the get-out clause for this one. This is one of those cases where WCAG 1.0 whussed out.
44:03 Checkpoint 3.4: use relative rather than absolute units in markup language attribute values and style sheet property values. Note the additional sentence in the technique though: If absolute units are used, validate that the rendered content is usable. Within reason, fixing a layout to a certain size may still be ok, if testing shows that it does not impede actual users. Taking it to the letter, this would preclude anything, even max-width.
46:00 It’s about making your content fit the window But that can be counter-productive. On large screens, it results in overly long and difficult to read one-liners, for instance. Not completely clear-cut in my opinion. If all else fails, offering alternative stylesheets can be the answer.
55:03 Checkpoint 5.4: if a table is used for layout, do not use any structural markup for the purpose of visual formatting. Structural markup here refers to additional structural elements and attributes specific to data tables, beyond the most basic row and cell definitions. For instance, this would mean not using TH in a layout table only to achieve bold text. This also invalidates a common misguided practice of adding a summary of “layout table” to a layout table.
56:23 Checkpoint 10.2: until user agents support explicit associations between labels and form controls, for all form controls with implicitly associated labels, ensure that the label is properly positioned. Make sure your label is next to your input Not just that it’s next to it, but that it’s in the correct order: for most label text, it should come before the input; for radio buttons and checkboxes, it should come after the input. Otherwise assistive technology such as screen readers trying to compensate for the fact that you didn’t use an explicit label will get confused and read the wrong text as the label for the input.
57:08 Checkpoint 12.4: associate labels explicitly with their controls. The difference between implicit and explicit labels: explicit labels use the FOR attribute to specify which form control they refer to, and don’t just rely on being next to (or wrapped around) it.
1:02:48 Checkpoint 9.5: provide keyboard shortcuts to important links, form controls, and groups of form controls. They can use those keyboard shortcuts if they want to… The root of the problem is, though, that they can conflict with your browser, operating system or assistive technology controls. So users may not want to use them, but - while trying to access a particular function - they trigger them. Accesskeys can effectively hijack a user’s control; for instance, imagine defining an accesskey “F”…this would prevent an Internet Explorer user from jumping to the File menu.
1:03:35 Checkpoint 10.5: until user agents render adjacent links distinctly, include non-link, printable characters between adjacent links. Make sure there are spaces between links. No, not just spaces. This checkpoint refers to old browsers coupled with old screen readers which had a serious issue with links, even when they were separated by spaces. That’s why the checkpoint specifies that these separating characters need to be printable…simple space is not enough, and that’s why many people started using pipe characters,   and so forth. However, this is a non-issue from a technical accessibility point of view, as any browsers and assistive technologies in use today should really recognise adjactent links, even in the extreme case where there’s absolutely nothing between them. Although from a usability point of view it’s still a valid point that you shouldn’t have links butt up against each other.
1:03:57 Checkpoint 11.3: provide information so that users may receive documents according to their preferences. Basically it’s saying: provide alternatives. Glossed over a fairly big kicker here: taken at face value, this means that your site needs to be fully multilingual and multimodal. What if a user has a preference for Mandarin Chinese? Simple graphics instead of text? Sound rather than visuals? This is one of those priority 3 checkpoints that seem impossible to fully implement, which makes sites claiming AAA not achievable if taken to the extreme.
1:09:35 Checkpoint 5.6: provide abbreviations for header labels. If you keep your header label short you can then explain them with a longer description. No, other way around: you can have long header labels, but then provide an abbreviated version which is read out so the user doesn’t have to hear the long header all the time as they travel through the table. The ABBR attribute of table headings works in exactly the opposite way of ABBR elements. See the explanation of the ABBR attribute in the HTML 4.01 specification for TH
Filed under: Accessibility
Comments Off Posted by Patrick H. Lauke on Monday, April 10, 2006

Creating Accessible and Slimline Forms

Andy King (of Speed Up Your Site fame) has put together a nice little how-to for creating an accessible feedback form using structural and semantic markup. If I’m completely honest, there’s nothing here that hasn’t already been said before and posted on other blogs or web standards sites, but Andy does a good job of running through the process step by step, pointing out a number of gotchas along the way. Worth a look if you’re currently thinking about giving any of your forms a standards-based makeover.

Filed under: Accessibility
Comments Off Posted by Ian on Monday, April 3, 2006

Roberto Scano’s Journey Through Accessibility

Italian accessibility expert Roberto Scano has a nice guest article on Gez Lemon’s site: A Journey Through Accessibility.

From “tag generation” to the “WYSIWOYS generation”. Roberto Scano identifies web accessibility problems throughout the web generations, and summarises where we are now, and what we can expect for the future.

Also of interest: Pam Berman from the Bloomsburg University of Pennsylvania - Department of Instructional Technology interviews Roberto about several accessibility-related issues (part 1 and part 2).

Filed under: Accessibility
Comments Off Posted by Patrick H. Lauke on Monday, April 3, 2006
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