Web Content Accesibility Guidelines
W3C Standard 6, Guideline 7 - Ensure user control of time-sensitive content changes.
Ever Come across a webpage that is flickering so much it starts to give you a migrain? Ever been able to pay attention to anything on that page other than the flickering portions? I've been to a number of pages in my web-surfing days that have either an ad or some portion of the site that just has to have a flickering background for show. Features like scrolling marquees, flashing objects or backgrounds, and moving text or pictures, all are bad to put into a webpage just to have them. For accessibility reasons, it makes alternative methods very difficult to allow that screen reader to read moving text. In fact, they can not read moving text. I'll show a few items of webpage business that should be given control to the users for these kind of flashy gimics.
First, a Priority 1 item. Until the user agents are given the option of controlling the flickering on the users' screen, avoid flickering anything. If myself or any other user cannot decide to turn those flickering backgrounds off, it has been advised not to go with that option.
Priority 2's -
- When showing presentations or just changing the pages for the users, until the user agents allow for the controlling of the blinking, change the pages at a regular rate or don't do auto changes. Let the user decide when to change items.
- Whenever I am lookin through pages that have ads, next to the main content, that routinely move it really distracts me from the main material. Avoid moving objects or pictures so user agents have the ability to let the user understand what the picture or object is portraying. If movement is really necessary, allow for a stop or freeze action button.
- Currently, user agents do not allow or provide options for refreshing pages. This causes problems when a page periodically auto-refreshes. Until the user agents have this ability, do not auto-refresh.
- Last priority 2 talks about the auto-redirecting to other pages. User agents don't have the ability to stop auto-redirecting. For this, we should not use markup to redirect our pages. We have been instructed to allow only the server to perform the redirects.
The basic understanding of movement and flashing or flickering content is that if a site is going to have these options, let the users have a bit of control on how they move or how fast they flash and flicker. It is all about the users accessing the pages. If it is not easily usable or accessibily abling, developers should look how that page or pages is being used and revise it.
