Usability Tensions
We all know that we should strive to make our systems as usable by humans as possible right? Just slick and easy to use is always the right way to go? Well, there are some design and systems issues that pull us away from usability. Understanding these tensions can help us create better human experience design.
The first tension I’ll mention is between usability and security. Generally the more secure we make a system, the more inconvenient it is to use. Most financial transactions on the web, for example, are multi-step processes that may involve user-id and password, anti-phishing technology, and perhaps CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart). These inconveniences are necessary to protect users personal data and to prevent electronic thieves from stealing their data.
Think of the opposite - a completely usable and convenient system. You go to your bank where your money is kept in a pile in an unlocked cubby hole - you can just walk in without id and take or add to your money pile. This is a slight exaggeration, but meant to illustrate the point. Sometimes we need to inconvenience users to protect them and ourselves.
Another tension is in user expertise or savvy. Beginning users often need a lot more instruction and handholding, while expert users may find such handholding oppressive. I have seen some systems which adapt to user expertise. Certainly many software programs have tool tips you can shut off. A perfect system would automatically determine your level of expertise and scale appropriately. Dare to dream eh?
The final tension I will mention is a tension with flexibility and features. In one of my favorite books, Universal Principles of Design, it states the rule, “As the flexibility of a system increases, the usability decreases.” What they mean is that simplicity and usability go hand in hand. Think of Unix vs the Mac (of course now Mac runs on top of Linux). Unix has ultimate flexibility - as long as you know shell scripting and arcane commands. The mac is UI is very simple and easy to use. However, both have their places.
Try to understand your audience without letting them design your interface by committee. Remember the old joke that a camel is a horse that was designed by a committee.
