Success for End Users Is ...

A product's end-user experience is the cornerstone to its success. A good user experience doesn't guarantee success, but a bad one is nearly always a quick route to failure. However, experience quality is not binary—total malfunction is rare—but, surprisingly, mediocrity in user experience can actually be worse than complete failure. When something doesn't work at all, at least it's obvious where the problem lies, but something with intermittent problems—a shopping cart with a high dropout rate or a search engine that only 40% of the people can find things with—can make a product underperform even if the rest is perfectly designed. A mediocre user experience can go unnoticed and be the most serious problem in the whole business venture.

Note

Don Norman has some beautiful examples of unusable products in his book, The Design of Everyday Things. His examples illustrate that although we may not always know what makes a product usable, we can really tell when it's not.

What makes a good experience varies from person to person, product to product, and task to task, but a good general definition is to define something as "usable" if it's functional, efficient, and desirable to its intended audience.

... Functionality

A product—or a portion of a product—is functional if it does something considered useful by the people who are supposed to be using it. Each product has a set of things its users are expecting it to do, and to be considered usable it needs to be able to do them. This is a simple idea, but it is remarkable how often it is forgotten. For example, a high-end subwoofer came with its own amplifier and its own remote control, but—in the interest of minimizing controls on what was ostensibly a speaker—the manufacturer made some functions available only on the remote control. One of these was the control to switch between equalizer modes ("Theater," "Concert Hall," "Radio," etc.). Unfortunately, if the remote were lost, the amplifier would stay in the equalizer mode it was last in forever. So if the subwoofer was set on "Radio" and the remote was lost or broken, the owner would then have to listen to all music amplified as if it were a tinny talk show, with booming vocals and almost no treble. This defeated the basic purpose of having an expensive subwoofer in the first place: to make music sound good.

A more common phenomenon is the deep concealment of key features by the complexity or incomprehensibility of the interface. The classic example is the process of programming VCRs before the advent of on-screen programming: the functionality was so difficult to understand that it may as well not have been included in the product at all.

... Efficiency

People—on the whole—value efficiency, and how quickly and easily users can operate a product attest to how efficient that interface is. A product's interface may enable a task to be accomplished in a single step, or it may require many steps. The steps may be prominent or hidden. Maybe it requires its users to keep track of many things along the way. In the traditional perspective, these factors boil down to speed, how quickly someone can perform a task in a given situation with the smallest number of errors.

... Desirability

Although long recognized by usability specialists and industrial designers (and certainly marketers), this is the least tangible aspect of a good user experience. It's hard to capture what creates the surprise and satisfaction that comes from using something that works well, but it's definitely part of the best product designs. It's something distinctly different from the packaging of the product (the esthetics) or its marketing, but it's an emotional response that's related to those.

Usability and Design

Ultimately, usability is good design. That's not to say that all good design is usable since there are things that are well designed from one facet (identity, technology, value, etc.) that are not usable. For example, a lot of expensive designer furniture is beautiful and instantly identifiable, but often you can't put many books on the bookshelves or sit comfortably in the chairs. Similarly, the Unix operating system is incredibly elegant and powerful, but requires years of practice and memorization before any but the most basic functions are usable. Coke's OK Cola had brilliant packaging but tasted terrible. On the other hand, Yahoo! became popular by focusing so much on the end-user experience that their visual identity lacked any readily identifiable characteristics. In the end, despite all marketing efforts, products that are hard to use are likely not to get used much. People using an unusable product will either be unable to do what they need to do, unable to do it quickly enough, or unhappy as they do it.

There are, of course, exceptions to this: occasionally, a product will be unique, and people will excuse any usability problems because of its functionality (content management systems are a good example of this: they can be incredibly hard to use, but taming huge amounts of content is nearly impossible without them). However, those situations are few and far between. In almost all other cases, the usability of a product is critical to its success.