Tag Archives: usability

Web Accessibility: Small Flashing Objects and Text

The criteria for presenting small flashing objects and text on a web page varies depending upon the reference you use when it comes to defining what amount of flashing and moving is permitted on the web within the web accessibility laws. Of course, this changes depending upon which country’s laws are being followed as well.

The important point to consider is that you don’t let small flashing objects flash faster than 3 times per second. According to W3C.org:

The criterion is 25% of any 10 degree visual field, any single flashing event on a screen (there is no other flashing on a screen) that is smaller than a contiguous area of 21,824 sq pixels (any shape), would pass the General and Red Flash Thresholds.

Small Object Sized

That is an image the size of 341 x 246 pixels. The definition of a “general flash” or a “red flash” are defined below in the threshold definition by WCAG 2.0 Recommendation as:

a flash or rapidly changing image sequence is below the threshold (i.e., content passes) if any of the following are true:

  • there are no more than three general flashes and / or no more than three red flashes within any one-second period; or
  • the combined area of flashes occurring concurrently occupies no more than a total of .006 steradians within any 10 degree visual field on the screen (25% of any 10 degree visual field on the screen) at typical viewing distance

Squizlabs’ HTML_CodeSniffer describes this as:

The definition of small enough is given as “25% of any 10 degree visual field on the screen… at typical viewing distance”. This size, therefore, depends on the screen size, resolution, and viewing distance. The higher the resolution or screen size, the larger the permitted area.

Objects that flash and blink on the web page run the risk of initiating optically-induced seizures in visitors. According to WebAIM, no element should flash at a rate of 2 flashes per 55 cycles per second.  Using their 508 checklist, one or more elements that flicker on a page that does not meet this criteria is considered to fail, and will put someone at risk who is sensitive of optically-induced seizures.

W3C Recommendation 2.3.1 states that:

Three Flashes or Below Threshold: web pages do not contain anything that flashes more than three times in any one second period.

The intent is to reduce the chance of seizures since some people are sensitive to flashing on screens. This includes people with photosensitive epilepsy as well as photosensitive seizure disorders.

W3C goes on to further explain this is detail so that a writer could fully understand how critical it is to make sure accessibility standards are met. The other resources all show that optical seizures are the main reason why that this criteria is maintained. These sources differ in the timing of the flashing time limit but they agree about the results. So whatever source you choose consider your reader.

The web standards for moving and flashing text for web accessibility are found in Section 508 1194.22 (i), WCAG 1.0 A 7.1, and WCAG 2.0 A 2.3.1.

References and Resources

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Understanding Your Audience With Personas

When you first studied the fundamentals of effective writing, you probably learned what an audience is. For example, “My audience is people who like cats,” or “I am writing for people interested in learning about the Spanish Inquisition.” Knowing who your audience is helps you to tailor your style and the information you provide in a way that your specific audience will understand best.

However, it may not be that simple. You can sum up your audience in one lump statement, but doing so prevents you from understanding the diverse needs and qualities of those who visit your site. Fortunately, creating personas for your site is a great way to understand your audience and be a more effective writer.

What is a Persona?

In the context of web design and usability, a persona is a hypothetical user of your site based on real information you have gathered about your audience. Step Two Designs says personas “act as ‘stand-ins’ for real users and help guide decisions about functionality and design.”

Typically, you should have three to five personas that represent your site’s audience. According to Boxcar Marketing, ideally the personas you create should represent both your primary users and your secondary users. These personas should be similar in that they share a relationship with your site, but should be different enough to help you recognize variances between the groups actually viewing your site. Continue reading Understanding Your Audience With Personas

Interview with a Professional WordPress User Jason Meister

I had the opportunity to sit down with the Network Administrator of my company and chat a little about the WordPress site that we currently have.

His name is Jason Meister, and he is in charge of maintaining and updating the site on a regular basis. Those updates not only cover the necessary WordPress updates, but also updates to the content and layout as well. Keeping it inline with the company’s focus and target market.

Although WordPress is not his core function at the company, he has to insure the site maintains a professional look and feel and works well with everything else we have in the company.
Continue reading Interview with a Professional WordPress User Jason Meister