Efficiency in Design

Efficiency in Design

by Dr. Bob Bailey

July, 2001

(For the most up-to-date information, check out the most recent Web User Profile Statistics)

It is the nature of most engineering activities that designers never have enough time to truly perfect their products. Engineers are continuously confronted with the real-world constraints of tight schedules and limited resources. Designing websites is no exception.

Most website designers would like to develop sites that could be easily used by anyone who attempted to access their site. This is hardly ever possible. In the end, designers must wisely use the limited resources available to them to design websites that will accommodate the most users with the least amount of design and testing effort. The following example uses only four variables (out of many) to show how designers can effectively limit their many options. The data used in the example were recently reported by www.thecounter.com/stats (June 2001).

In each case the goal was to include enough options to handle at least 90% of users. To accommodate the largest number of users with the least investment of time and other resources, restrict design decisions to the following:

1. Design only for the Windows operating systems from Microsoft (these account for 93% of all operating systems being used):

Win 98 (72%),
Win 95 (10%),
Win 2000 (6%), and
Win NT (5%).

2. Design only for Internet Explorer 5 (77%), Internet Explorer 4 (9%) and Netscape 4 (9%). These three browsers account for 95% of all browsers being used.

3. Design primarily for 800x600 pixel resolution (53%), but also accommodate pixel resolutions of:

1024x768 (31%),
640x480 (5%), and
1280x1024 (3%).

These resolutions are used on 92% of all computers.

4. Design primarily for a 16-bit color depth (55%), but also accommodate color depths of

24-bit and 32-bit (38%), and
8-bit (5%).

These color depths are used on 98% of all computers.

Even focusing only on these four variables, designers would need to conduct 108 separate tests to determine how the interfaces will perform with the different combinations. For example:

Test 1 - Win 98 and Internet Explorer 5 and 800x600 resolution and 16-bit color
Test 2 - Win 98 and Internet Explorer 4 and 800x600 resolution and 16-bit color
Test 3 - Win 98 and Netscape 4 and 800x600 resolution and 16-bit color
Test 4 - Win 95 and Internet Explorer 5 and 800x600 resolution and 16-bit color
Test 5 - Win 95 and Internet Explorer 4 and 800x600 resolution and 16-bit color
Test 6 - Win 95 and Netscape 4 and 800x600 resolution and 16-bit color
etc.

In other words, unless there is a very good reason to do so, do not waste time designing for and conducting usability tests on:

The Macintosh, WebTV, Linux, Unix operating systems, or any Windows operating system prior to Win 95,
Any browser except recent versions of Internet Explorer and Netscape,
Monitors that have resolutions less than 640x480 or greater than 1280x1024, and
Monitors having less than 8-bit color.

As designers, we must clearly understand our intended user population, design specifically for them, and learn to systematically give up trying to accommodate all users. Our design time is finite and our resources are limited. We cannot design a usable website for everybody! Good designers make good decisions about what not to do.