By David Bomphrey, Senior Usability Consultant

"All too often in web design the experience of the user takes lower priority than other considerations, such as the appearance of the site. An attractive website may impress visitors initially, but this will be short-lived if the site doesn't allow users to accomplish their goals easily- a fact worth bearing in mind where the use of graphics is concerned." Marc Sparrow – Midnight communications.

Many people still browse websites via slow dialup modems, especially home users. Graphics are very "heavy" with regards to k size. This means that the bigger and more complicated the graphics and the larger the number of graphics, the slower the download speed for each page. As many people who have dialed up at home will tell you, this can be extremely frustrating and can lead to people browsing with pictures switched off or worse, going to competitors' sites.

The use of pictures in some sites is inevitable however. There would be little point offering a service such as www.multimap.co.uk or www.streetmap.co.uk if you were not going to use pictorial maps for example. In these cases a picture paints a thousand words and the circle or the arrow they use to pin point the exact area of search is an extremely valuable guide for users finding the area they are looking for.

In other cases such as news sites, pictures could be used to illustrate rather than describe. A good example of this on the BBC's website where the tone and the general topic of the story can be gained through a brief glance not only at the headlines but also via the main picture.

In a more detailed look at the current situation in the Gulf on one of the BBC's news page, however, a more detailed map can convey an enormous amount of information.  In this case, the map is many layers deep and although this type of information could be described in words, it would be a lengthy article and would not give a clear understanding of the relative positions of each of the elements and strategies. This particular implementation can be used as not only a good example of where interactive maps can provide real power to the web builder and the consumer, but also examples of where implementation can cause usability problems.

On this BBC news page, some of the colours used (contrast) and the fact that bitmap graphics (fuzzy edges to words) are used make reading some elements on some of the views more difficult than it should be. (The most readable colour combination has been found to be yellow on black)

It may not be intuitive for users to actually click into the various areas of the site. Although it is interactive, the interactive elements do not stand out that much more obviously than the non-interactive ones. This is because the common experience is to look for something obvious (blue underlined on white background instead of black text, or something button-like (i.e. beveled etc) to press on. This information is then displayed in text underneath the picture itself and could easily be missed by users.

Furthermore, in this case, the layers of the map are displayed in tab like buttons. In general this is a good idea, as it is becoming a web standard but in this case they look a little detached from the map and are also placed on the right hand side. Users are beginning to expect tabs at the top of a screen or screen element or as a menu bar on the left side.

Overall, interactive graphics are very inaccessible to the visually disabled. Although Alternative Text, and Title Tags can be employed to help mitigate these issues with flat images the same cannot really be used to help blind or partially sighted users understand the interactive maps and charts and the information they contain. Flash also falls into this category. There is currently no comprehensive solution to this problem because maps are inherently and have been historically a visual medium. Macromedia, the manufacturers of Flash, are attempting to make this technology accessible by allowing screen readers access to the text embedded within it and the navigation but the technology is still being ironed-out. It will be interesting to discover if and how this will make interactive maps more accessible.

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