BANNER ADVERTISING AND ACCESSIBILITY

BANNER ADVERTISING AND ACCESSIBILITY
------------------------------------

1. Definition of Banner (http://www.webopedia.com/TERM/b/banner.html):
---
Also referred to as a banner ad, a banner is a typically rectangular
advertisement placed on a Web site either above, below or on the sides
of the Web site's main content and is linked to the advertiser's own Web
site. In the early days of the Internet, banners were ads with text and
graphic images. Today, with technologies such as Flash, banners have
gotten much more complex and can be ads with text, animated graphics and
sound. Most commerce-related Web sites use banner ads.


2. Standards for Banner ad:
(http://www.iab.net/standards/uap/index.asp):
---
Starting in August 2002, the Ad Sizes Task Force began a process to
reduce the number of ad sizes for the purposes of reducing the costs and
inefficiencies associated with the planning, buying and creating online
media. The result was the Universal Ad Package, a set of four ad sizes
that all compliant member publishers have agreed to support:
* 728 x  90: gif/jpg weight limit: 20Kb - flash weight limit: 30 Kb -
max animation length: 15 sec. - no border
* 300 x 250: gif/jpg weight limit: 20Kb - flash weight limit: 30 Kb -
max animation length: 15 sec. - no border
* 160 x 600: gif/jpg weight limit: 20Kb - flash weight limit: 30 Kb -
max animation length: 15 sec. - no border
* 180 x 150: gif/jpg weight limit: 15Kb - flash weight limit: 20 Kb -
max animation length: 15 sec. - no border

The IAB's new wave of voluntary guidelines includes seven new
Interactive Marketing Unit (IMU) ad formats; two vertical units and five
large rectangular units. The new voluntary guidelines join the roster of
recommended guidelines that the IAB already has in place. These units
are currently being introduced by Web publishers and are designed to
enable marketers to utilize greater interactivity as well as expand the
creativity in their online messaging. The IAB's Ad Unit Task Force will
meet on a bi-annual basis to examine the effectiveness of existing ad
units; review proposed new ad units; and issue updated voluntary
guidelines as appropriate. A full definition set for all these banners
is available in the IAB web site
(http://www.iab.net/standards/adunits.asp).

The sizes are a 120 x 600 "skyscraper," a 160 x 600 "wide skyscraper," a
180 x 150 "rectangle", a 300 x 250 "medium rectangle", a 336 x 280
"large rectangle", a 240 x 400 "vertical rectangle" and a 250 x 250
"square pop-up" ad. The IAB also said it would no longer include the 392
x 72 pixel banner from its recommended sizes, since that size is rarely
used.



3. Accessibility for Banner ad:
---
What is the main problem for the banner ads? A lot of banner ads are
simply images (jpg and gif) and must respect the guidelines for
Core 1.1 (http://www.w3.org/WAI/GL/WCAG20/#text-equiv).
We can divide the banner ads in six big groups:

- text ads
- image ads
- flash ads
- javascript/pop-up ads
- skyscreaper ads
- Webmercial ads


a) Text ads
Text ads are the "simply ones" that are available. For accessibility for
the low vision people, the text must be expressed in % or .em for the
the user to resize it. Text ads must advise the user that the link is an
advertising link so the suggestion for the code is:

<a href="http://www.banneradserver.ext?id=xxxx" title="(banner)">Product
name or Promotional message</a>


b) Image ads
The user must have the possibility to know that the image is a banner
ads so the combination of "title" and "alt" attributes can help during
the navigation (with eventually a "longdesc" if there is the necessity
to describe the banner AD images and/or animation). Here is an example:

<a href="http://www.banneradserver.ext?id=xxxx">
   <img src="banner.gif" width="120" height="60" border="0"
alt="(banner)" title="Product name - promotional message in plain text"
/>
</a>

If the banner contain an animated gif this can also cause reading
problems to the user with cognitive disability or for low vision people
and if the are screen flicker - Core 2.3
(http://www.w3.org/WAI/GL/WCAG20/#flicker).


c) Flash ads
What about Macromedia Flash animated banners? Following the guidelines,
also the object tag must respect the guidelines for Core 1.1
(http://www.w3.org/WAI/GL/WCAG20/#text-equiv).

<object type="application/x-shockwave-flash" data="movie.swf"
 width="250" height="250" title="(banner) Product name - promotional
message in plain text">
   <param name="movie" value="movie.swf" />
   <a href="http://www.banneradserver.ext?id=xxxx">
     <img src="noflashbanner.gif" width="250" height="250" border="0"
alt="(banner)" title="Product name - promotional message in plain text"
/>
   </a>
</object>

In the example, if the user has not Flash support there is the image
alternative version with the possibility to follow the link, also if the
image is not available.


d) javascript/pop-up ads
Some times there are banner ads that are generated by javascript code.
This means that the user must have script engine activated.
The banner also request to conform to Core 2.1
(http://www.w3.org/WAI/GL/WCAG20/#keyboard-operation). Javascript is
also used for pop-up the banners. Pop-up windows are ads launched into a
new, smaller browser window when a page is loading. Pop-up windows can
easily be targeted to launch over a specific page, a feature that not
all interstitial technologies provide. Pop-up windows are most commonly
run by attaching JavaScript launch code to a banner ad. This allows the
pop-ups to be frequency-capped or targeted using any ad management
system's targeting capability. Because pop-up windows are simply smaller
browser windows, they can contain any standard Web display format,
including HTML, GIF, JPG and Macromedia Flash.


e) Skyscreaper ads
Also called Redwoods or Towers, these ads are usually found off to the
sides of web pages. They provide a large advertising space while
utilizing normally unused web space. These kind of banner is activable
only by the "onmouseover" on "onclick" events so these are not
accessible and not conform to Core 2.1
(http://www.w3.org/WAI/GL/WCAG20/#keyboard-operation). For these banners
must be offered an alternative version, like for the Macromedia Flash
example.


f) Webmercial ads
Unlike banners, webmercials feature full-screen animation accompanied by
professional voice-over and sound effects. They appear in the primary
browser window between Web pages for 5-30 seconds. Webmercials can also
be shown while viewers are waiting for a file to download or a search to
be completed. Because of this unique delivery, webmercials are much more
effective than TV commercials-even for branding purposes. These ads, due
to the multimedia equivalents requirement, must conform to Core 1.2
(http://www.w3.org/WAI/GL/WCAG20/#media-equiv).

Received on Sunday, 21 September 2003 08:10:44 UTC