Thoughts on "Simple is Better"

Simple user interfaces are catching on. Sparse user interfaces generally make for products that are easier to use. The main Google search page is a model of simplicity, and it is one of the most visited pages on the web. It is almost difficult to do anything but search when you visit the page. But the simplicity of Google's search page is likely something that has been under constant attack.

Usability trades off against features. Forces within Google are no doubt constantly pushing to add features to the search page. The temptation is great for two reasons:

• Since the page is so popular, you can guarantee traffic for whatever link or feature you add to it. When Google releases a new product, think of how tempting it must be to add a blurb to the main search page urging visitors to check out the new product.
• Google could implement more flexible and customizable searches if it included some options on the main search page.

Resisting this temptation is hard. Whoever is resisting it faces "death by increment" arguments: "I know simplicity is important, but don't be unreasonable! What could be the harm of adding just one new feature to the page?"

For this reason, it's helpful to define usability metrics up front. The metric might limit the amount of time it takes for a typical user to accomplish the most common and important tasks. Or it might measure the likelihood that a novice user will perform these tasks successfully when visiting the page. Each new feature Google adds to the page will tend to increase the amount of time and decrease the likelihood that a visitor will perform the most common and important searches successfully.