Behind a website's superficial appearance lies its fundamental understanding of user behavior in an interactive service. Choices such as whether the "buy" button is red or orange or whether the navigation menu runs across the top or down the left side are much debated, but make at most a few percent difference in usability. In contrast, the design ideology can make or break a site.

I see three contrasting approaches to design, which I have dubbed mastery, mystery, and misery.

Mastery: Empowering Users

Search engines are the archetypical embodiment of the mastery ideology. They place users firmly in the driver's seat and take them where they want to go. You can get anywhere on the Web using a subservient interface that accepts any words you throw at it and serves up a simple, linear list of rank-ordered choices.

Not coincidentally, ever since the WebCrawler debut in 1994, users have proclaimed search as one of their main activities on the Web. Being in control feels good.

Complying with design standards and conventions is one of the main strategies for strengthening users' feelings of mastery. Understanding what they're being shown and knowing what they must do to achieve a desired effect -- that's the stuff of mastery.

In the mastery ideology, the designer's job is to provide the features users need in a transparent interface that gets out of the way and lets users focus on the task at hand. Leading e-commerce sites typically understand this; they sell more when users focus on products rather than on puzzling out the design's surface manifestation.

Mystery: Obfuscating Choices

A simple user interface is not boring. It excites users because it lets them connect with the content and engage the company behind the site.

Website designers stare at their designs all day, every day. In contrast, users visit for four minutes and then leave. Very different experiences in terms of what's boring and exciting. Don't aim at an exceptional experience for yourself and your team members.

Our testing of the usability of Flash designs clearly demonstrated the fallacy of the mystery ideology. Almost every time a design employed a non-standard scrollbar, users failed. Our test users typically overlooked numerous options because they didn't realize that the highly decorated or otherwise unusual scrollbars actually served a function.

Users don't want to admire the scrollbars. Truth be told, they don't even want scrollbars as such, they just want to access content and have the interface get out of the way.

Even designers who believe in user mastery can be tempted to taint their designs with shades of mystery. It's easy to delude yourself that an ornamental feature will attract users. For example, most users disliked the category name "lifestyle" on bbc.co.uk according to the British government's user research. One user said, "Lifestyle, what the hell's that? I like gardening, it's not my 'lifestyle.'" Another user said, "I would never have looked at a lifestyle section, it doesn't mean anything to me." (It's long been a usability guideline to refrain from using fancy terms to label navigation categories; use specific, everyday language instead.)

Users don't like websites that patronize them or tell them what to do. They like websites that support the goals of their visit.

The website of J.K. Rowling (author of the Harry Potter books) might be an exception to the avoiding-mystery rule. The site feels more like an adventure game, but that’s appropriate because its primary purpose is to feed fans rumors about Rowling’s next book. The site contains many an oblique element. There's no way, for example, that you'd ever guess that a bunch of paper clips are a link to the FAQ. The site violates most guidelines for hypertext links: it has no perceived affordance of clickability and only the most tenuous of metaphors maps the reference domain to the target domain.