Tangled Web Usability

Make your pages usable

• Avoid the hype
• Most visitors are first-timers
• Some monitors are more equal than others
• Avoid frames
• Use backgrounds sparingly
• Don't require images.
• Don't cut yourself on the edge

Avoid the hype

On the web, copy is harder to read when it's full of hype. Jakob Nielsen says,

When people read a paragraph that starts "Nebraska is filled with internationally recognized attractions," their first reaction is no, it's not, and this thought slows them down and distracts them from using the site.
--Jakob Nielsen, Alertbox for Oct 1, 1997

Say what you want to say and leave the hype and verbiage to annoying commercial sites. The three keys are:

• Be concise
• Make the page scannable (with lists, for example)
• Avoid market-ese ("amazing new...", "first time in human history", etc.)

Combining these three techniques resulted in a 124% improvement in readability in the test described in the above Alertbox column.

Most visitors are first-timers

Most people have 28.8 or slower internet access.

If the number of internet users is doubling every year, then half of the users have been using it for less than a year.

Some monitors are more equal than others

Not everyone has a 21" monitor. Nothing's worse than having to scroll back and forth to read something that won't fit on your screen. This can be a problem with big images or tables.

Frames suck (most of the time)

First, frames take up screen space. But more importantly, they break the primary navigation method of the web. A page in a frameset has no URL. Jakob Nielsen has an entire article on this.

Use backgrounds sparingly

It's easy to get carried away with background images. They can add personality, but you need to be careful:

• Keep them very muted.
• Don't use straight lines.
• Never use letters or numbers.
• Provide a background color of the same general shade.
• Avoid the temptation to use star fields. (Then you have to make the text white, which has its own problems.)

Don't require images

Many users keep image loading off. Be sure to provide enough text for them.

• Use ALT text for all images. There is some art to writing good ALT text.
• If you use image maps for links, always provide text links as well.
• The top of the page should not be all image.

When you do have images, make them as small as reasonable, and compress them as much as possible. That generally means JPEG for photos, and GIF for line drawings. For more helpful hints, visit the Bandwith Conservation Society.

Don't cut yourself on the edge

Not everyone has the latest beta of Netscape Assimilator with

• Java
• Shockwave
• Xtreeme Video
• Braun Smell-o-vision and
• Kai's Waffle Varnishing Power Miter Box

You don't have to write for the lowest common denominator, but bleeding-edge technology will limit your audience drastically.

Java

All implementations crash regularly.

JavaScript

Most users either don't have it or leave it off.

Shockwave, VRML, etc.

Only a tiny fraction of users have these, and most won't go out to get them just to see your site.

Audio

(RealAudio, e.g.) can be used as an extra (recordings of mission control at critical points are particularly exciting).

Document author: Kevin R. Boyce (email: Kevin.R.Boyce@gsfc.nasa.gov)
This page was last modified on 5-Jan-98 at 11:46 AM