Resolution and window size 
Resolution. 17 inch screens have been affordable for quite some time now and have more or less become the standard screen size. With this increase in screen size there has also been an increase in screen resolution. Research shows that only 3,2% of European surfers still surfs in 640 on 480. Even 800 on 600 is only used by 35,8% of users, compared to 45,4% of users who prefer 1024 on 768. The research also shows that more than 10% of surfers use an even higher resolution.

Window size. Obviously, it's best to take the above figures into account when you're making a web site. Optimizing your site for a certain resolution means disregarding a group of users who have made a different choice. However, these figures don't really tell the whole tale. After all, just because someone has set the resolution to 1024 on 768 doesn't mean that he or she actually uses the entire screen size to surf. People with big screens often open several windows and put them next to one another. A flexible or liquid layout that adapts itself to the resolution and window size of the user is an absolute necessity.

Reality 
Higher than 800 on 600. Few web masters seem to realise that it is perfectly possible to make a layout that looks good in different resolutions and window sizes with one and the same html code. Our research has shown that 80% of Belgian sites doesn't make full use of the available space when the width of the window exceeds 800 pixels.

800 on 600. But it gets worse. Only 65% of all Belgian sites manage to look good in a resolution of 800 on 600. A disappointing 14% doesn't even succeed in using the entire screen space in 800 on 600 while there are horizontal scrollbars on 21% of the sites. One could assume these sites are optimized for a higher resolution but even that isn't the case. A lot of sites actually manage to produce scroll bars in 800 on 600 while not using the entire screen space in 1024 on 768.

The solution 
Obviously, optimizing a web site for one resolution is not a solution because it leaves a lot of users out in the cold. During user tests, a growing number of test users actively remarks on a bad use of the available screen space. Avoid this irritation and tackle this issue on your web site by using a 'liquid layout' that makes your site look good on all resolutions and window sizes. UptoMusic and Wanadoo prove that it can be done.

The liquid layout and other practical tips are also elaborated on in the article 'Liquid layout' and in our Usability workshop.

Els Aerts & Karl Gilis