Designing usable web pages
Understanding how people view web pages
The wandering eye
People find it difficult to read from a computer screen. They tend not to read in the same structured way as they would read a piece of paper. They skip around the screen, jumping to anything that appears to relate to the subject they are looking for.
You can track the user’s eye movements on a page with specialist ‘eye tracking’ equipment. You should use these for larger projects – try eyetracker.co.uk for more information.
Figure 1.
The way a typical user might skip about a page – in 800
x 600 screen resolution.
Screen resolution
It is important to know the screen resolution (size of computer monitor)
that people are using. The following table shows that 16% of users have
an 800 x 600 screen resolution. You must check your site in a variety of
screen resolutions.
| Screen Resolution | Percentage of users |
|---|---|
| 1024 x 768 | 62% |
| 800 x 600 | 16% |
| 1280 x 1024 | 13% |
| 1152 x 864 | 2% |
Screen resolution statistics for March 2006 – source thecounter.com (sample of 227,066,290 unique visitors)
Figure 2. The same screen as Figure 1 – in a 1280 x 1024 screen – the user is almost seeing a different web site
Printing pages
Many users like to print web pages to read or file. It is best practice for
all web pages to be printable, and this is easy to achieve using an alternative
printable style sheet. You can hide unnecessary elements and re-format
the font sizes and the layout using a printable style sheet. For more information
on printable style sheets visit http://www.alistapart.com/articles/goingtoprint/.
Layout – using space without confusing users
Since users skip all over the screen, rarely reading as you want them to,
you should be careful about the proportion of the screen given over to
certain elements. It is important to look at a site and realise how much
of the screen (especially on a smaller screen) is given over to content
and not to navigation, advertisements, and so on.
Look at the same Google News page shown on an 800 x 600 screen resolution, to see just how little of the screen is actually taken up with content.
It is best practice to make sure that the page is dominated by the actual
content. Although navigation, advertising, site identity and other page elements
are important, people need to understand at a glance what each page is about.
Try to keep your page content as short as possible. In the words of web usability
expert Steve Krug: “Get rid of half of the words on each page, then
get rid of half of what’s left.”
Figure 3. Google News shown in an 800 x 600 screen resolution with the actual page content highlighted.
Download times
Many small and medium sized businesses and home users still use a standard
dial-up connection. So although faster broadband connections are becoming
more common, a significant proportion of your customers are still frustrated
by slow download speeds.
As you get to know your users, you should be able to find out what type of connection they will be using. There are very few businesses or organisations whose users all have a broadband connection.
It is best practice to test your web site using a dial-up connection to make sure that it loads in a reasonable time. There are no hard-and-fast rules about page size or download times, but the user should be able to get at least some content within five or six seconds. If a page is likely to take some time to download, you should warn the user and if possible give an alternative.
Browser compatibility
Although most users browse the web with Microsoft’s Internet Explorer,
there is a variety of operating systems, browser versions and different browsers
in use. It is vital that your site functions in at least the most common
browsers. The table below shows browser statistics for September 2004. Although
a significant percentage of users are using the current version of Internet
Explorer, there are many who use alternative browsers.
Figure 4. Browser stats for March 2006. Source thecounter.com.
You can check how your web site looks in most browsers and various operating systems at browsercam.com.
Style and design vs. usability
People often think that a usable web site will be boring and unattractive.
When you define the objectives for your web site, you will probably specify
that the design needs to complement your existing branding. Your designer
should always aim to create a web site that fulfils this brief.
However, the ‘look and feel’ of a web site should never hinder the user. The site is being developed for the customer, not the owner. You should aim for a web site that looks good, but test it fully during development to make sure that your selected user group can use it effectively.
It is important to realise that the use of Flash in a web site does not
make it unusable. In fact, the interactive nature of Flash can make an extremely
usable web site when it is introduced effectively. Because of download speeds,
however, you should provide some alternative content for users with outdated
browsers and slow connections.
