Re: Action Item from 24 August


Thank you for writing this up!

Based on all of this information, do you think there is anything missing 
from the current draft of the reformulation?  Is there something else we 
need to add?

Do you know how this changes as the eye is less able to distinguish between 
colors or shapes?

What about people with Attention Deficit Disorder?  Does the delay in 
movement apply to them as well?  It is my understanding that it doesn't, 
that any movement will continue to distract them. Lisa, can you comment on 


At 03:08 PM 9/19/00 , Marshall Jansen wrote:
>Action Marshall: write up something about visual presentation. Look at
>principle 4 for requirements that are not included.
>Ok, I've let this sit long enough.
>First disclaimer: I'm not a visual media expert, but I have had some
>Second disclaimer: this probably needs some work to turn it into a useable
>The sighted user, when presented with a web page, follows an ingrained set
>of 'rules' as to what draws the eye first. The eye is drawn to several
>different things, but motion, size, and contrast are the primary
>The most attention-grabing item tends to be a combination of all three... a
>large, high contrast, 'moving' image will immedaitely draw the eye. In this
>case, motion is a misnomer, it might not be motion, but simply a color change.
>Strobe effects tend to have the greatest effect at grabbing attention. The
>BLINK tag is an example, and images that flash two high contrast colors are
>another. While the initial blink draws attention, the eye can eventually
>tune it out. You can cause the viewer to repeatedly be drawn to this item
>by implementing a delay. For example, a short (1 second) strobe effect will
>immediately draw the eye. If the author continuously strobes, the brain
>will eventually tune it out, but if a 5-10 second delay is in place, then
>every time the strobe effect happens for that 1 second, the eye will be
>drawn to it again.
>After gross motion and strobe effects, the eye will tend to be drawn to
>images rather than text. Brightly colored images tend to have a greater
>capability at attracting attention than black and white, and high-contrast
>simple images are more attracting than low contrast and complex images...
>the eye will be drawn to a 2-color high contrast icon than it will be drawn
>to a black and white photo.
>That said about images, some types of text are more visually
>attention-grabbing than images. First off is size... large text is read
>first. Secondly is a contrasting color, if your document is full of plain
>balck text, then red or blue text will 'jump out'. Obviously text that is
>both large and a contrasting color will be more visible on a first glance
>that text that is just big or just a different color.
>After those issues, the next is a font modificatioin, be it bold, italic,
>or a new font altogether. Bold text tends to be more noticeable, just as if
>it were a different size. In contrast, italic text tends to be LESS
>noticeable than standard text. Font changes are hard to judge in general...
>it would have to be seen on a case-by-case basis as to how significantly a
>font change draws the eye.
>Finally, after all of the above is said and done, the sighted user will
>'default' to an initial point on the page, if there are no visual cues to
>draw them in. This tends to be cultural/language based. English readers
>will track to the top-right corner of the page even if there are multiple
>'articles' visible. (i.e, if you have three separate columns of text, each
>one a separate 'article', English speaking readers will read the leftmost
>one first.)
>The next logical step would be to create a chart of all of the possible
>elements (strobing images/text; large, high contrast text; bold text, etc)
>and 'rate' them by how much they draw the eye. However, I don't feel
>particularly qualified for that task, as once you get into nuances, my
>understanding breaks down (i.e. which draws the eye more? Bold text that is
>a contrasting color to the rest of the document, or a small icon of high
>contrast colors? I personally have no idea, and would have to say 'it's
>about the same')
>Marshall Jansen  //
>Senior Web Developer
>VP of Marketing and Outreach
>HTML Writers Guild, Inc.  //  <>

wendy a chisholm
world wide web consortium
web accessibility initiative
madison, wi usa
tel: +1 608 663 6346

Received on Wednesday, 27 September 2000 16:16:31 UTC